Umbilicus Immortalis

Minions are still able to die to Infernal Legion while affected by life flasks.
Repro:
1) Go to hideout
2) Equip Umbilicus Immortalis
3) Equip Blood of the Warrior life flask (lasts a long time but doesn't heal enough to counter Infernal Legion)
4) Equip any minion skill gem (tested with Tame Beast and Skeletal Sniper)
5) Socket Infernal Legion support gem in it
6) Use flask as minion's life approaches 0
7) Observe that the minion dies