tl;dr: I've heard it said that a lock can be defeated using a typical road flare to cause lock failure. I tried that today on a rather weak lock and it failed, so rest easy.
I decided to try that today when a roommate's cable lock stopped working permanently locking his bike to our porch. We can't get a pair of bolt cutters so hopefully this thing isn't stolen overnight. Nice bike in a bad neighborhood.
My attempt to defeat the lock with a flare failed. There was substantial deformation of the cable but it did not fail with simple and direct heat application over a period of 10 minutes. Subsequent mechanical attempts with wire cutters and "forceful pulling" also failed.
The flare I used was not actually a typical road flare. It was a backfiring fusee. Very similar to a road flare but designed for lighting fires. This device burned hotter and faster than a regular road flare would have.