Asharah, I agree that just saying "no" does not equate to making a scene. It is quite possible to gently push the box away, stand up, and say "sorry, I'm not doing this."
But I can see where these sort of things happen - people don't want to say no (eg, "How can I say no to my best friend of 10 years?"), or they're afraid they'll be seen as a "mean" person. And sometimes, the rudeness is just so incredibly shocking, that people just go along with it because they're literally stunned over the whole thing. On this forum, it's so common for someone to say "I wish I had been thinking - I would have told (rude person) to get bent." Yes, people need to grow a spine (spines?), but I can also see where they just go along with the rudeness.
I can see your point twinkletoes, but in this instance, the BM's had two hours to stand up for themselves - it wasnt an instantaneous thing. Moreover, if one does not stand up for themselves, or isnt looking for advice on how not to let it happen again, imo, one loses the ability to complain about the situation, because it then becomes their choice to be complicit in whatever situation they find themselves in. I dont mean to be mean about that, and I fully recognize that the submission site is for the sole purpose of complaining about it after the fact, but in principle, I just dont have sympathy for those (myself included) who arent
able willing to stand up for themselves when they are clearly being taken advantage of. Shyness, or non-confrontationalness, is totally understandable, but again, I just cant be sympathetic to someone that says "I could never stand up to her, can you imagine what the response would be??" but I can be sympathetic toward someone that says "I am so shy, and afraid of the response if I stand up to her, but I dont want to be taken advantage of like that again. What do I say next time that is non-confrontational, but gets me out of the situation quickly?" I hope that makes sense.
I myself have a problem thinking quickly, and so when I go into a situation where I might be put on the spot I try to put up my guard, and I always take my time responding, even if I have to change my mind during the course of the conversation (for a real or imagined reason). Then, when I do get taken advantage of, I replay the situation in my mind, imagining better responses, and resolve not to do it again. Inevitably it happens again though!

Anyway, it's just my opinion, and probably not worth very much...