Feed the Beast

Turns out that it will clean your inventory(unless keepInventory is set to true)... and Ars Magica stats.

Interesting. The ars magicka stats, I mean. I expect losing all my items when I self-destruct, but Ars Magicka stats vanishing?
I've only heard of such things when your player data gets messed up, or with outdated versions of Sync.

The pack I'm using does have an outdated Sync mod (2.1.1) installed... Time to update

It only happened if you died as a shell and it could be seen quite easily as shells didn't have the same player data. For example, you wouldn't have any of the same AM stats for each shell, and vanilla ender chests wouldn't link up between shells.
Cleaning your inventory, tough, makes perfect sense; you're a freaking bomb. Do explosions leave much behind in Minecraft?