Butane isn't generally a preferred solvent, i suspect people use it because it's easily available in relatively pure form. I'm far from an expert but brands typically advertise something more like a supercritical CO2 based extraction process.

Which i guess is to say, I think they blew up their apartment because their goverenment doesn't allow commercial chemistry to be applied at relevant scales to marijuana, users are then jumping into suboptimal home-made solutions.