Sending Feech to prison was the wrong move

He just did 20 years in the can, old man now looking to spend the rest of his remaining life in jail.

Why wouldn't he just become a rat at this point? Even in his brief time outside he saw and knew enough to make a killer testimony. Even if testimony isn't enough, they are building a rico against Tony, every bit helps.

He is dead either way, makes sense he would do a hail mary. Tony already made Ritchie and Ralphie disappear. Why send a senile old man who has nothing to lose and HATES YOU, to a place he can still cause trouble. Of all the people Tony has hit, this would have been the most sensible one