In many ways, the issue here boils down to what happened to these guys in the context of having joked around with each other in a private conversation. And what happened is tragic. Someone got fired for it. Someone's livelihood was affected by this. Not to mention the emotional shock this surely caused.
What's right and what's wrong? Sometimes the answer isn't easy. Private conversations between friends have been known to have content that surely someone, somewhere is bound to find offensive.
The other effect is that there are people who hear what they want to hear --or read what they want to read-- rather than what was actually said or written. All you have to do is watch Fox News, CNN or, for that matter, any news show to see this effect.
HN is perfect proof of the fact that this happens. I've seen it a bunch of times and I've experienced it myself.
A joke is a joke. A dumb comment is a dumb comment. It happens. And, if it hasn't happened to you (plural) yet it surely will at one point or another. I don't know any perfect people.
What saddens me in this case is the firing. I think that was wrong. Way wrong. And absolutely unfair.
One thought that went through my mind is the idea of surveillance cameras picking up private conversations. One could argue: Well, be aware of it and act accordingly. Then there's the question, perhaps legal, of what actually constitutes a private conversation protected by privacy laws. Does one have the right to publish the contents of someone else's private conversation, whether it was overheard or picked-up via intentional or unintentional surveillance? I don't know. It's a bit disturbing because of the potential implications on the assumption of privacy in otherwise public settings. Now you have to look around before having any kind of a conversation because you don't know if anything you say, offensive or not, might come back to pummel you on the Internet.
I would not be surprised if lawyers are involved at this point. I'd certainly go talk to one right away if I was on the receiving end of something like this and it affected my job.