> Publicly bad mouthing the > company you work for > is definitely grounds > for termination

Having not read any of the tweets in question, I can not say what the content is about.

However, according to https://www.hg.org/legal-articles/can-you-fire-someone-for-t..., speech about working conditions and union organising is protected.

I suspect none of us armchair lawyers will come up with a simple way to analyse these tweets with a lot of context that isn't available.