I always put my phone in flight mode whilst on stage, as otherwise you get horrible RF noise coming through instruments, amps etc. A drummer friend recently depped in my band, and I became aware he was answering texts, FarceBook messages etc. in between songs. I meant to have a word with him afterwards but forgot.
Yes your drummer was right, but there are better ways to deal with people than the way he chose. Seems like you'd be best off out of it, for your own safety at least.