Unfortunate indeed for your friend; sorry to hear that. This certainly illustrates why rope can be useful. I would prefer something more substantial than paracord or slippery, nondynamic dyneema

I do indeed carry mason's twine/paracord routinely - contemplated use is for lashing/tying. Depending on the situation and terrain, I might throw in a cordelette (20-30' of 7mm kernmantle) or bump it up to something longer like 30 meters of real rope - http://www.rei.com/product/885246/edelweiss-discover-8mm-x-30m-super-dry-twin-rope - , thus adding about two pounds to the overall weight of my pack.

If real climbing is anticipated, I have my bag all packed and ready to go - 60M of rope, helmet, harness w/slings, biners, and selected goodies - a good ten pounds plus of character building weight. There have been occasions where that has just been a good start.

It all comes down to how much rope for anticipated conditions, but something is way better than nothing.