I would have left not long after the "big pivot". I've seen it quite a few times before, if the tech team is not involved in 'pivot' decisions, it means the execs have no clue what they are doing. Typically they go to a trade show somewhere and immediately want to 'pivot' to the latest craze.

I had my own 'pranad'(sp) too a previous project, one that was even slightly sneakier as he did fake demos of the features he was asked to write -- still manage to stay 18 months, and every single line he ever did had to be replaced afterward.

And in the UK, the sort of toxic situation with the manager would guarantee a 'constructive dismissal' payout too.