It sounds like it was so crowded that it was hard to have a conversation that could be considered "private", that is, not easily overheard. To me, this would be like saying something offensive at work while on an elevator or in the corporate cafeteria. I may be looking directly at someone else while saying it, but if others can easily overhear it, is it really "private"? Having said that, I would not have tweeted their photos, but I might have said something directly to them without or "before" involving staff. . .which might also be considered a violation of the Code of Conduct.