I think it is simpler than we think. Here's my understanding:
Option years don't count on the AAV. He got $6M with a $4M buyout, so it's $10M on the 2022 tax line.
They don't make adjustments after the fact. $10M counts against 2022, so the $4M buyout is subtracted from the remaining option AAV, so $26M/2 is $13M, but subtract $4M from $26 and it's $22M/2. That's $11M on the tax line for 2023 and 2024, assuming they take the option.
I could be wrong.