Language issues have historically cost the world a lot more than a forfeited pool game.
I remember watching a TAR podcast with Shane and Efren. Justin asked Efren if he preferred slop rules or call pocket. He asked three different ways, then Shane asked the same question twice before Efren finally understood the question. Efren's conversational command of English seems to be pretty good, but still, you will see certain words or phrases that he gets confused. Shane likely has to deal with the same problems.
I'm sure that even if a rule was communicated that you had to actually physically mark your pocket like in some leagues, Shane would have complied every time, with nothing more than maybe an eye roll at an obvious shot like this one was. Was it a language issue here, or did he decide to flagrantly defy the rules and shoot without calling his pocket? Only one possibility makes any sense to me.