I've come across this problem a lot though not on bike's,first time was years ago when asbestos free linings and pads started to be introduced on commercial vehicles and buses,there were a lot of issues with glazing and bonded linings becoming detached!
It seemed at the time the new materials didnt handle the heat like the old stuff
However my point is this problem is back and I've seen it a lot on ford transits and the like, OEM pads detaching from the backing way before they are half worn and worse still 52 seater coach's the brake caliper's of which require a 2 man lift to set in place so have huge pads to match,I've stripped any number of these only to have the friction material break up like a digestive biscuit!!
Glad your ok mate and hope you get some joy out of HD on the subject.
And now your all relaxed try not to think about the consequences had the pad jammed between the disc and caliper