Maybe because if he hires a professional one, it will engage with the fields and he might not sure if the secret remains secrets eventho he writes nda, so maybee if he gets someone who's basically owns nothing, he can keep him under his control (?)
A guy who has nothing to lose and thinks "maybe i should go back to jail" is more likely to break the nda lol
I imagine a professional dom would be used to ndas, and theyd be risking their own job if something went awry
But i guess he just likes the risk/a guy who was a murderer is sexier??? Because he could actually kill, and the danger is better? Idk
obviously for the plot, do u want him to get a profesional, both are buisness story ends in 1 chapter?
Couldnt he hire a professional dom instead