Hitting a hard 16 vs a 6 is one of the dumbest moves you can make using basic strategy. Using standard card counting I've never seen an index for it and I'd think it's so ridiculously negative that it will in all practicality never occur in a 4 deck shoe. Therefore I think it's safe to say that just using the information of the cards already played, as he claims, there will never occur a situation in which the best strategy is to hit.
If he is using some sort of sequencing or shuffle tracking or some other technique to know there is a high probability of a low card occuring then this begs the question, why didn't he double down? Now I haven't done any math so don't take this as definitive proof but I can't see there ever being a situation in a 4 deck game where the best strategy is to hit a hard 16 vs a 6 and not stand or double.
If he is using some sort of sequencing or shuffle tracking or some other technique to know there is a high probability of a low card occuring then this begs the question, why didn't he double down? Now I haven't done any math so don't take this as definitive proof but I can't see there ever being a situation in a 4 deck game where the best strategy is to hit a hard 16 vs a 6 and not stand or double.