In Bloodsport II Master Sun is shown as an old man retelling Alex's story to his students in the future, but in this movies he is killed making that impossible.
When Alex goes to the warehouse from the note, he slides over a table full of money, in the next shot the money is gone from the table and isn't on the floor either.
Stelio removes his headband during a fight, but then it reappears and disappears again during the same fight.
JJ Tucker has a shaved chest in scenes where he is on the bleachers, but a hairy chest during his fight scenes right after.
When the judge shoots the arrow at Alex, it hits the tree behind him. He then shoots another arrow, and it hits the tree behind in the same spot. The original arrow was never removed by Alex, but it is gone before the second arrow hits.
Alex learns from Sun "the Iron Hand," the move which is pretty much a super power. Alex never forgot it, but he doesn't even bother to use it on Beast, which would have won him the match in an instant.