L's behavior during hospitalization was indeed very similar to D's! However, in terms of overall personality, it was actually more similar to Caeran.
The possibility that Deacon wouldn't take the blame for Aris was probably only if he hadn't joined the band! His personality was prone to causing himself trouble. And if Aris really faced charges and was sent to prison, his mother would do everything possible to get him out (her feelings for him were quite complex...).
And joining the experiment was actually something Deacon agreed to himself, to save his fellow inmate; if it were Aris, he would definitely not do such selfless things... He might just be gnashing his teeth in the prison and thinking about how to escape.
