Dragon Suicide Glitch

In a recent post on YouTube, a user put up this video of dragon slaying himself..(posted below)

Meanwhile, redditor TheAnswerIsScience managed to replicate this glitch with the instructions below: (unverified)

Have him auto you as you walk out of his aggro range with thornmail on and he will do this. 

You could say this is exploitable but how often does on build a thornmail and on top of that I can only think it being useful early game. In which case who rushes thornmail.

You can be sure I'll never be doing such a foolhardy thing...