LRNAD90
Adventurer
As long as the tether is connected to a different (secure) part of the vehicle (assuming this is common sense), and of sufficient strength (usually a winch extension cable or similar), it should still arrest the flight of a departed shackle or tow hook.
Of course, like anything else, there are other factors involved. This works particularly well with winch recoveries, and can work with kinetic strap recoveries, if the pulling vehicle is not 'sending it'. But under the right circumstances (foot to the floor recovery vehicle), I'm sure anything is possible..