Did the other team have Lydia? She can ignore block revive. I think there's a mythic champ who can too, other than those idk of any way to bypass block revive.

Lydia doesnt work that way with active revives on your team though.  She denies an enemy revive and then revives an ally.  She wont allow a blocked revive ally to be revived by another ally. 

So a few things can cause a block revive not to work.  Warmaster / Giant Slayer, Phantom Touch, Soul Reap, or what I suspect happened in this case, Edward's Passive.  Basically it needs to be the damage directly from the skill thst kills the enemy to block revive them.  If the damage comes from any of the other sources the champ can still be revived.