So this is interesting.

I had a very similar problem back in October where the foot rest button was completely missing. The result was that the foot rest was stuck out - which is obviously not allowed for take off. I spotted it just as boarding completed (I was about to push the foot rest back in).

I didn't get any compensation from BA CS when I complained but onboard the option presented was to the back of the PE cabin into an empty row of 4 (from the bulkhead seat) which I accepted and some bubbles from club as an apology.

But BA's CS seems to have stopped avios compensation for me certainly - I had to complain about getting gum stuck on the back of my jeans from a dirty seat the other day and got "I completely understand why you’re annoyed your clothes were ruined due to chewing gum on board our flight".

And then a 3 paragraph explanation as to why they'd had to move me mid flight (which I'd made clear I understood in my original email but was there to explain why I knew the gum had come from their seats).

I kid you not.