Dire Shockballs with 0 duration do too much damage

• OpenMW Version: 0.50.0
• Linux Xubuntu Dodge
• English
• Expanded Vanilla + some changes

Beware of the Sixth House adds the Dire Shockball spell to Ash Ghouls. When I'm hit but such projectiles, I get around twice the expected damage. If I change the duration from 0 to 1 second, then I can the correct damage.

Is the damage applied multiple times when the duration is 0?