They must have had a terribly weak case.
The only logical answer.

When he plead to the judge he had to admit he was the shooter.
He said something like “ I was hiding in the closet I jumped out and said this is a stick up and I started shooting”

As I said read the book so long ago.

Anyhow not on this case however, in general guys that flipped ended up doing 6,7,8,10 years and they sold their sole for that.
I’m sure majority would have taken 10 with a guilty plea rather than 6 and flipping.

Just to put it in perspective Peter Pan got a dime piece for biting a car, and Nicedemo got 25-50 for being the get away driver with one body.