If the victim lacks a rescue vest and it is too difficult to pull them out with a snag line, try a cinch line rescue. The cinch line is an extra line above the snag line that attaches with a carabineer. The send line forms a loop that tightens around the victim enabling a more controlled pull. Consider tying a stopper knot in the middle of the line to limit how tight this loop gets. Here is an article demonstrating a cinch line foot entrapment rescue: Cinch Line Rescue.
NOTE: There are many variations of cinch methods you can choose from. A huge advantage of a cinch over a snag line is you maintain control of the victim. This can be really important since the victim probably has serious physical injuries and might not be able to swim.