I thought I made people mad by ordering a curry chicken sandwich in a student-ran shop in college, but I hadn't paid attention to an announcement that was made at the end of the class and I accidentally interrupted the minute of silence for a terrorist attack that had happened a few days before
I remember a pause for a minute's silence announced in the upper concourse of a train station (UK) last year. It was disconcertingly comedic as the people walking in either on the phone or with a friend were very confused at why everyone inside was standing motionless and glaring at them.
I think I was working in that station on that day, because I have a very similar anecdote. Actually someone came to buy a ticket, and was annoyed because they thought they might miss their train having to wait for the minute's silence to end. Not even the most callous passenger I've come across either.
Similar situation, I was at an antiques shop with my parents, on November 11th, which here in the UK is a day of remembrance for people who died during WW1 and WW2. We're observing the moment of silence, when an American guy walks in, notices the silence and loudly exclaims "Wow, who died? It's like a mausoleum in here!" Someone, thankfully, took him to the side and quietly explained what was happening. He did apologise afterwards. I found the whole situation very funny.