+1. If one knows they should have stowed one's bags in the Oh and did not, what more is there to say?

But assuming the OP was still fumbling through their bag when the door closes, the FA is right in the request. While many FA's willl gladly assist in stowing bags, it may be a bit presumptuous for a pax to expect the FA to be their porter. Seems like this incident is due to a miscommunication. Perhaps asking the FA to assist without simply holding up the bag would be more appropriate in this case.

Perhaps the FA was lazy(always possible), but perhaps they are having a bad day. Perhaps the FA is easily offended by pax whom they presume to not respect their authority. Who knows?