There's not a lot you can do in that situation. There's so much slack in the line at that point, there's not much of an effective way.

You could quickly execute the roll cast in hopes of getting the hook to set. Or you might try to strip as much line as you can as quickly as you can with one movement and raise the rod behind you (if there's room).

Sometimes fish strike at the most inopportune times. (like getting a drink of water, or being distracted by wildlife....)