What should I do when my opponent mouseslips?

Sort:
EnCroissantCheckmate
 

My opponent clearly mouseslipped (on move 26) with check, and I didn't know what to do. I could either capture the rook, which almost guarantees a win, or I could move my king so that my opponent could play the move he meant to play. I chose the latter option, but I didn't realize that my other rook was hanging until I had already played Kf1. 

 

What should I do when my opponent (clearly) mouseslips?

ChessDude009

accept it

insatiable27

lol but good sportsmanship.