I've thought since this accident in Masterton, NZ (and the recent rather distressing apparent similar one in the States) that some kind of glassfibre or similar containment device or guard for the propane bottles/hoses would be a good idea...prevent them coming into direct contact with wires and other nastys (more wires, I guess), should there be an unexpected wind shift, or the pilot fail to see the wires.
Then you just have a snared balloon to contend with, rather than an unsurvivable fire.