First I just want to say that I agree with you, that was an explosion; explosion and detonation aren’t necessarily the same thing. Loud noise and rapidly expanding gas = explosion. One correction though, which is that a shockwave is supersonic, and just judging by the fact that burning fragments were on the floor and not punching through the wall, I’ll guess it wasn’t supersonic.
Ah I wasn't aware of that distinction, I thought a shockwave was any sudden rise and subsequent fall in pressure. Learn a new thing every day, thank you!
Still an explosion!