When I tried this while my opponent had scarab (myself with 3 burrowed devs), the scarab died and all was perfectly normal. Did your opponent play anything sux? that may have been why it didn't do it.
List of stuff I've discovered (To be editted):
- If any creature is hit by the pand, this won't happen.
- If a creature was hit with a pand earlier the same turn, this won't happen.
- Works with Burrowed or Quinted critters.
- If you only have 1 Burrowed/Quinted critter, it won't happen. (But flynn got it to happen with only one dev. o_0)
- Any permanent can break the lock if it's ability is used and not canceled.
- If the ability of a permanent is used, then canceled, the lock stays. (But canceling Poseidon can break the lock. o_0)
- Doesn't happen with upped pand, and opponent having 2+ quinted critters.