Never gotten the including yourself scratch two glitch. Have gotten the repeatedly exploding detonator. It exploded about 20 times and then stopped. (Really big black mark where it had been lol) So far ive seen it happen once, had it happen with a det i threw twice. I have no idea why it happened, it seemed to happen randomly. It would only happen with the Sonic Detonators though. I tried staying still until it finished and then throwing a det in the exact same angle and position, and...nothing.