In general, when one person goes all in, the win / tie detection can be completely off.
I just got another example, where there was a set in the community, and I had a king + 5 in my hand and won against an opponent who had a king + queen in her hand. (None of the cards on the table were as high as a queen, so set + king + queen should have won outright.) The opponent in question had gone all in, but she didn't even get a portion of the pot back.