It was a tiny current, with respect to the vertical area it affected. Simply inflating their bcd a bit would have broken them out of it where then they could swim away while dumping excess air from the bcd to prevent a fast ascentThat looks terrifying. Bubbles like to go up, anything that prevents them from doing so is a powerful force. Thanks for posting.
If I saw someone trapped like that, I would say that a basic principle of Rescue is that you wouldn't do anything that was likely to create a second victim. Even sending a line looks like it would be more likely to get tangled up than help.