Just an Idea, I probably would have pulled rope in myself as I Followed the climb. When I got enough rope above the cut, tie a figure 8 on a bite and clip it into my harness with a locker. Problem solved and climbing resumes safely. Sometimes no communication is best.

we always just do 3-5 big tugs for every major thing:

leader tugs to say off belay
then another to say they're off
then the ropes are pulled and the seconder tugs to say that's them
then leader tugs again to say they're on belay
seconder tugs to say they're climbing

we've never had any problems with this

Yep, radios are the best solution though, having been an advocate for years, I have to admit I've had a ton of random radio problems in the last year. When they don't work, you need a backup plan like those discussed here.

As for your problem.... If you were carrying a cordalette (as we all should for use in a self-rescue situation) you could have tied a friction knot above the sheath cut and tied/clipped it into you harness - not ideal but would afford some piece of mind. Oh, but i forgot, you're a Sporto; you probably don't know any of this traddie stuff! :^D. Sorry, just couldn't resist!