I won the league and Cup, final of CL coming up and I had my last league game automatically scheduled 4 hours before CL final and I'd no way of getting to a computer.
Won league game 6-0 but 7* striker got injured and I'd no other back ups so 3* AMC got put in that position by game engine.
Checked game later to see I'd lost CL 3-2, opponent played a 5-4-1 defensive formation, I was 2-0 up with 15 mins to go and he scored 3 in last 15 mins.
Hard way to lose a treble as it was my fault really.