I'd love an explanation how these comments are actually discrimination. Mentioning someone's gender or religion isn't discrimination. Was anything said that someone wouldn't want to hire female researchers? Isn't the second one expressing that he or she wishes to accommodate people taking their religion serious?

Someone revealed to a colleague that they have attitudes of being annoyed with other colleagues as a result of the reproductive or religious choices of those other colleagues, and you think that because the revelation didn't happen at work, the attitudes will be of no interest to HR? Think again. Worry less about what you say and more about how you feel and act. It's not ok to be disrespectful, and if you don't want consequences for it then take greater care who you do it in front of.

Voting to close because we are not lawyers, so cannot speak to the legality of HR action in the UK.

It should not be too hard to find out who the snitch is (and you should definitely do that). But WHY would this person would do something so awful. What was their motivation? Was there some axe to grind here? Your other problem is to figure out why HR would make use of the snitch rather than tell him to shut up and go find something useful to do.

I cannot cite anything here, hence not posted as an answer, but I have in the past received training as a manager on Discrimination in the Workplace, and in that training we were taught that if an out-of-hours event happens as a result of the workplace then it is treated as the workplace and in law discrimination is handled, investigated and dealt with as if it happened within the workplace, Since you are meeting a group of people that you only meet because you met in work and work together, this may be seen as a workplace event- hence the investigations. I am UK based.

@MarvMills that's quite interesting. A lot of us there are old uni mates but there are some people we only met through work. We don't all work in the same departments though.

@anonymous_George would your colleague say that colleague C has "gone and got himself cancer" as though it was a misdeed that the speaker is somehow the target of? I recommend against grumbling about colleagues in the presence of colleagues in general, and even more so if the grumbles touch on protected categories such as religion, parental status, marital status, or health. Which when you think about it pretty much all grumbles do.

@gnasher729 Find another word than “discrimination” if you like, the point is that it creates an hostile environment. It's certainly not harmless fun or valid criticism The question is a good one and even people who did bad things are entitled to be treated fairly and try to protect their careers any way they can but I think even the OP realises it wasn't OK to say those things.

@KateGregory you know what? I can actually imagine that sentence, but as a "I've just trained colleague C up on SAGE and the poor bugger's gone and got himself cancer." I appreciate it's Brit humor at its finest but there would be no malice involved either way. Obviously Researcher A is not a "poor bugger" though as hearty congratulations were given to her and she was over the moon.

Those comments, while offensive, were just people chatting in a context which they thought was "off the record". This is fairly ordinary stuff. Perhaps someone with clarity-of-thought and a little backbone should have spoken up and said something to the offenders when the comments were made? That would have been an appropriate way to deal with this. Instead, some reprehensible snitch has silently jotted down the comments and passed them onto where these comments can do real damage. Best course of action here is to socially ostracize that snitch.

This is scary stuff. It feels like you've gotta give barium meals to people before you decide whom to socialize with. No this is not discrimination, it's barely even banter. Accept this useless comment with my condolences on your situation.

"It'd be nice if [Muslim colleagues] could put a recurring meeting in their calendars for prayer so that I can schedule properly [discrimination]" Actually, I think this is a reasonable suggestion, though I'm sure it could have been better presented (i.e. tactfully and to the relevant parties directly). If someone wants to block out time for something, a calendar entry is the way to do it (at least in companies that generally schedule things based on that). One of the lead engineers here who is in meetings most of the time blocks out "office hours" so he can be around his desk for the team.

@Kevin I agree. That's actually a rather courteous thing for someone to do in a workplace which may support many religions and its easier to mark your calendar than it is to have everybody remember everybody's religious observations. I also an bothered by the pregnant one. If the phrase was "I'm quite cross that just as I found the perfect researcher she's gone to another state" there would be no discrimination. The benignness of these two examples suggests to me that either HR is being rediculous or there is an undercurrent in the situation, making these two quotes, out of context...

... a poor representation for what actually occurred. Perhaps it was not the pregnancy quip itself that has HR's attention, but the context around it. That context might be very benign, or it might have been a very dark conversation regarding women. We certainly don't have the context here on SE, but you may be able to think back and identify something intangible that HR may be grasping at that you can adjust.

@teego1967, as any experienced politician will tell you, there is no such thing as "off the record", sooner or later, someone is going to talk. If co-workers are together talking about things to do with work, they have to understand this could impact the workplace by carry-over. If it impacts the workplace, then it is a legitimate HR matter,

Someone in your social group really is a jerk

@Relaxed: The woman that is supposedly discriminated against is stopping to work at the company for some time, by taking advantage of laws in the UK that guarantee pay while she is having a baby and a safe job to return to. Mentioning that a woman is pregnant is not discrimination. Would you fire her manager for making sure that he has a replacement while she is off work?

@gnasher729 What nonsense is that? “Mentioning” that a woman is pregnant isn't what that was. Politics aside, are you really not able to see how being on the receiving end of such a comment could be uncomfortable?

I just want to say that, as a Muslim, I find the second suggestion totally reasonable and not discriminatory at all. It's the professional thing to do, but it's probably not done because the times shift frequently.

One general comment: There is a difference between general conduct outside of work, and keeping company secrets secret. You ordinarily (at least in my area) sign a contract dictating that you never divulge proprietary information, and that's a 24/7 obligation. There are other areas where expectations are placed at work that have no real or pretended application outside of work: your employer ordinarily does not tell you how to dress after hours unless it's way out there (indecent or whatnot).

I do find several things unfortunate in this: that this conversation was reported to HR by a faceless coward, that they were said in the first place, that the attitude present was in a place that could easily say such things, and that in your posting sees it as innocuous and the only unfortunate thing you really see in the situation is that the fabric of faintly Dawkinian conversation happened to fall in HR's lap.

you should tell each member of that group an ugly story, but each time with a different twist. Once you got invited by HR, you will learn who the little snitch is.

What happens in Vegas does not always stay in Vegas.

Well you could ask who reported this and ask to face your accuser and raze a grievance against them. Or Grievance against the HR manager for damaging the work environment .