Yes, but that applies to china mobile chargers and a lot of other devices that nobody worries about (and also to CFDs and any led lamp that might be today in your house)
Of course it's not. You weren't talking about one, you asked how a LED lamp can burn your house down. It can.
Personally, I can't see how someone could legitimately blame Philips for a Hue-connected-but-unsupported third-party bulb starting a fire, but I don't doubt some will try.
Funny thing though, but that AC/DC converter is manipulated by firmware activated by a wifi protocol. If the fire only starts when the converter is activated into its highest conversion rate in a particular sequence by certain commands sent across that wifi protocol and those commands are being chosen by a user of an app on a mobile device two rooms away, is that a software issue? It's certainly a gray area.
And of course it's not a software issue