This involves a gate agent and not only cabin crew, and not the kind of thick passenger who is funny in a cute way, but the slightly annoying, rude kind... I was a student, waiting to board an early morning flight from OSL to ZRH. After the annoucement that the flight was overbooked, there was a brief moment of total silence - enter the thick passenger: from 10m away, trying to look very important and busy, wearing a slick business consultant style suit and tie, he shouted out loud in his most impatient voice, for everyone to hear, adressing the tall and very handsome gate agent - "Hey you, Tarzan! I have a full price business class ticket, and I'm in a hurry, you better give me a seat right now!"
I instinctively made eye contact with the gate agent, to show my solidarity, and apologize on the other persons behalf. The gate agent briefly looked at me, smiled, and carried on doing his job, professionally and efficiently, unaffected by the rude guy.
After all passengers with assigned seats had been boarded, I was called over to the desk, and got an upgrade to business, which he handed to me with a big smile. The guy who had shouted "Hey you Tarzan" was completely ignored, and was left standing there.
I certainly didn't expect to get on that flight myself, I had the cheapest possible student fare, and no assigned seat. Unlike all the business people on the early morning flight, I wasn't in a hurry, and being a student, I would have been happy to wait for the next flight, and simple meal voucher would have been more than enough to make my day; but of course joining the plot as it unfolded was more entertaining
Later, the Maitre de Cabine (SR cabin manager) apologized to me - very unnecessarily, but again very professional - that they didn't have enough business meals, and gave me a full size bottle of champagne, Nicolas Feuillatte. I kept it for a long time, and later used it for a special occasion, with a toast to the gate agent, cabin crew, and a special toast for the thick passenger.
I hope the guy who "volunteered" not to board the flight learned his lesson...