Charnier's accent
For the first film, Charnier's 4 or 5 lines of English dialogue didn't bother me. Perhaps Rey had a dialogue coach, or the lines were just so minimal to not be of much notice.
But here, Rey is allowed to go wild. His accent is completely Spanish, with nary a trace of French inflection. I'm surprised that no one in the crew took notice, or perhaps he just couldn't do it.
Of course, as unusual of a character as he is, Charnier could be a man of French descent who was born and/or raised in Spain. Or perhaps Alain Charnier is simply a French-sounding alias for a drug lord who is actually a Spaniard. Doesn't really fit the spirit of the films, but possible.