downgrading ipod touch 4 (Apple Device Knowledge Required)?

i downgraded my ipod touch from 6.0 to 5.1.1 using my own AP Ticket from the SHSH blob. i wold my friend that i could help him do the same but it turned out he did not have a saved 5.1.1 blob, therefore no AP Ticket. what would happen if he tried to restore his iPod with my iPod's AP Ticket? would it work? and if so would there be any strange side effects?