Feel the same way. Just like to know in a timely manner, once had one overturned about 8 hours later and that one bothered me.Yes I've seen multiple ffpc trades reversed when accepted or offered in error and I don't really have a problem with it when it was clearly an error.
I think proper etiquette should be to notify your trade partner that you accepted an offer in error, and I always tell people if you inform me of that we don’t need to wait for the FFPC to reverse it if you tell me that .
Last year I kept getting multiple variations of offers that included me sending Trey McBride and the 1.05 (Triflex league). I kept rejecting. Finally he sent me one for McBride only, not the 1.05. I still sat on it for 16 hours before accepting. About an hour later he had FFPC reverse it then sent me the same offer I'd already rejected and said, "It was meant to be this one." Really rubbed me the wrong way because it seemed disingenuous, like he just regretted that I accepted it. I'm in multiple leagues with this guy and every one of his offers is an instant reject from me.
I do think that there are guys who take advantage of FFPC's trade reversal policy. I triple-check offers before I send them.