Is there any trust involved in connecting to a watchtower? How can you issue a punish transaction without having the private keys?

@LN+: The watchtower only stores copies of pre-made transactions. On seeing a revoked state on-chain, it can deobfuscate it and publish is as is. No changes can be made.

You can connect to multiple watchtowers, I am making a post with more information

Thanks for the answer!