Yes. My SET amp was damaged (the capacitor below the tube and then other things, it was not easy to repair it) when an El-34 tube was blown up. In fact, I was in front of the amp watching how the tube was blown up, I powered the amp down but the damage was almost immediate.
Can using a bad tube hurt an amplifier?
If you're using a tube for a while, and everything's fine, and then voltage changes over time gradually, and then it damages an amplifier? are amps Built with controls to prevent that from happening?
How can you trust using a tube if it potentially could harm an amplifier?
Assuming You're using the correct tube in the slot provided.