Structure of Acetone Enol Radical Cation

Ketone, Radical Cation and Its Decomposition. Part 3: The structure of acetone enol radical cation.
This structure is the product formed in the McLafferty rearrangement of the 2-hexanone radical cation. From which of the C-atoms in 2-hexanone is the hydroxyl hydrogen coming from?


Figure. The UMP2(full)/6-31G* optimized structure of acetone enol radical cation.