Hmm ... it's borderline whether there is anything noteworthy going on. One can also say Smith charged, but this is rarer, or Smith is called for the charge, which is fairly common. Nonetheless, the term doesn't act like most verbs, in that other forms don't come up much. The analysis I've inferred from watching countless games is that "charging" is short for "charging foul" or "charging violation" and "charge" means "to commit a charging foul". In particular, you wouldn't say "Smith charges down the floor" even if that would be a fine description of Smith's aggressive dash, for fear of saying that Smith is committing a foul. At the very least there is a separate sense of charge.