I'd actually be somewhat uncomfortable with the use of "goatse" as a joking reference in sample code, as in that whiteboard anecdote.

Not personally -- in the pub you should expect far fouler than that from me. ;) But since "goatse" refers unambiguously to something sexually explicit, I'd be hesitant to use it in a professional context except in a sort of antiseptic explanatory way: "Well, you should probably know that that's sometimes called the 'goatse operator', which refers to a brutally explicit image on the net."

I'd expect my colleagues, regardless of background, to be adult enough to handle discussing the topic in the abstract. But other usages are dicey. Here in the US, they're also legally hazardous... but I'd go beyond that and say that I believe in the reasons those laws were passed, and that our industry, with its dreadful gender diversity ratio, has a long way to go making our workplace environments welcoming to all.

Avoiding the word "goatse" on workplace whiteboards is very different from avoiding it on some random website you clicked to.