It is possible your tank was playing with a controller--that can make communicating harder. Also, was the conversation during or in between fights? I am too busy healing to even think of looking at a chat box for anything more than pre-determined shorthand (eg. one RM group decided to macro DD if shiva cast diamond dust since i was having trouble spotting it--i'm legally blind.) when a fight is going on. Further, if the tank did jump it's entirely possible they didn't / don't even know what Shield Oath is. That's annoying, but it's the truth.

Talking about someone like they aren't there is rude, though. If their performance did not seem satisfactory to the group, they should have been kicked. There was no need for drama.