I think it's a pretty immature and childish thing to get upset at the attendant in any case. Unacceptable behavior from adults, honestly.

They're doing their job same as I would in their place. Nothing either of us can do, and they really have no involvement in the first place. Blaming the attendant is what you'd do if you weren't emotionally mature enough to accept your own mistakes.

There’s a difference between blaming them and being a little annoyed at their callous, semi-aggressive response.

No one likes being called stupid. It’s unpleasant and completely unnecessary. I try to not spend time with people like that.

No one is blaming the attendant. People are reacting (or not, as some claim) to their attitude.

The side issue of blame can be taken out with a different example: You stub your toe. A person sees. Suppose that they either wince in sympathy, or laugh derisively.

Do you feel the same about that person either way? For avoidance of doubt: Are there any situations in which your future behaviour towards them would depend on which of these 2 reactions they gave?