To take with a pawn or a rook, that's the question

My final game in the Slow Chess Quad was a very interesting tussle where I only got a break when my opponent, playing very well, made the decisive choice: To take with a pawn or a rook?

A match where I managed to play without any major blunders, though I made an important mistake where I went from a winning position to a drawn one, and more importantly I felt - to a position where black got the initiative and I was left defending for a while.