i used to have friends like your drummer but thankfully i've weeded them out of my life.
if you gave him notice in October, then he's had plenty of time to find another gig. ( wanna bet why he didn't get another gig…). using his logic, HE should've given you notice in october that you owed him money. fair is fair, right? seriously, i'd just nicely tell him that 6 weeks cancellation ( or whatever the time is ) is perfectly reasonable and your band owes him nothing.
if you gave him notice in October, then he's had plenty of time to find another gig. ( wanna bet why he didn't get another gig…). using his logic, HE should've given you notice in october that you owed him money. fair is fair, right? seriously, i'd just nicely tell him that 6 weeks cancellation ( or whatever the time is ) is perfectly reasonable and your band owes him nothing.