I got this feel, coz he was supposed to be really close to Rudi, almost like a father figure. But as I see it, Luca is kinda distancing himself from Rudi. So I'm pitching that he did this coz... he doesn't want Rudi to sacrifice his life for him again.
Is.....
Just plain second chance. To maybe correct the death of the other people that helped him...? Perhaps...?
Luca was shocked about his aunt's new attitude towards him. So i guess he didn't really particularly wished to have a do over with her.