Personally, I wouldn't have written back at all, just stopped showing up.
While it does suck, some people don't like confrontation face to face like that. I know I sure don't. I fired a guitarist by simply changing our band members on our myspace page, because I knew he was gonna freak, yell, curse, go on a long tirade, and possibly hit me. I also knew that I would get really angry and probably do/say things I would regret. I didn't want to deal with all that so I just made it clear he wasn't in the band anymore. Not that i'm a wimp, I just didn't want to deal with it.
You could have called? And hung up if the guy got rude.
Also, firing someone in a passive-aggressive manner, IMO, especially to avoid confrontation, that wouldn't keep someone from going to your house or some other locations to confront you. Seems to create a false sense of security.
If you have a band member who has anger issues, dealing with them or replacing them sooner is a better move. Since you seem to have anger issues, I suggest you deal with them sooner rather than later.
Good luck.