"I don't know if you've already heard this one, but sometimes using a Bucket to retrieve a source block of liquid blood returns a Water Bucket rather than a Blood Bucket. Not a world wrecking crash like me last one, but very annoying in the early Survival game."

source: http://www.minecraftforum.net/forums/mapping-and-modding/minecraft-mods/wip-mods/1445975-evilcraft-open-source-v0-9-3?comment=525

Should be fixed in CyclopsMC/CyclopsCore@db2a30b.