opening multiple seals

[Terminal_Vertex]

Hi everyone, loving munchkin! Recently picked up Zombies and Apocalypse and having lots of fun surviving a zombie apocalypse! :D

Anyway, here is what happened (using only apocalypse cards):

-Player A kicks open a door to reveal Cthulhu so a seal gets opened. (bad stuff: dead)

-Four Horsies wander in. (bad stuff: lose a level and open a seal).

-A helper (Player B) joins the battle.

-Through interference they can't win and have to run away.

I understand for multiple deaths, only one seal gets opened.

What if the players run from the Horsies first, and both fail and then one (or more) fails against Cthulhu.. is that 3 seals that get opened (for a total of 4 because of the initial one at the start of combat)? or is the idea that only one seal should be opened at the end of a failed combat?

We ended up ruling just one seal at the end of combat.

Many thanks :)