A yellow 2×2 square at back left, plus the front-right corner. The back and left sides show no yellow.
Algorithms
F R' F' R U R U' R'
8 moves
YOURS
Built from
Sledgehammer + Sexy move
Trigger
Sledgehammer · backwards
F R' F' R
Trigger
Sexy move · backwards
U R U' R'
Relations
Your algorithm backwards
R U R' U' R' F R F'
solves OLL 33
That's why your scrambles are never the inverse of the algorithm: you'd be practising OLL 33 without knowing it. CubeDojo builds a random state with this case and checks it comes out.