Yes, I also despaired. I was horrified, doubly so as I regard BBC4 and Wallander to be elevated above the general level of illiteracy that is creeping in on TV. Yet a few minutes later they used the subtitle 'praxis', hardly in everyone's vocabulary. SORRY: just noticed other references to this word above. Praxis is correct in the context used, it's not an error, though it's a rare word, not one I'd put in a subtitle myself, I mean, you're supposed to be translating for quick comprehension, not showing off.
I put it down not to illiteracy, obviously whoever captions this programme just isn't, but to poor management and poor checking of work. I do a lot of proof reading in my line of work and I am ruthless about it, but also use others to double check the double checks.