fat will do that to me - or eating too fast. Or some meats just don't sit well sometimes. I ate half a reuben sandwich once and felt the same way. I eventually threw it up - and at the time I was at least three years out of surgery. BUT - those have a lot of fat, and corned beef may be one of those meats my stomach can't always deal with
not sure that sounds like true dumping - that usually also involves racing heartbeat, sweating, diarrhea, chills. I think it either didn't agree with you, or you might have just eaten it too fast.