Failsafe didn't catch a no flow jet (non conclusive:aq)

[Craigorypeck]

I had massive knock on cylinder 4 of my direct port setup yesterday..
My WL is set one click anticlockwise from false triggering, or one click clockwise and it activates failsafe.
So how come it didn't catch this?
I have followed the instructions regarding flowing the jets out of the engine and setting up the 6 bars on gauge with manual test. At 30psi boost this could have killed that cylinder... My knock sensor saved it i think.
My thres is set quite low to activate at around 10psi boost.
Any tips welcome.
Cylinder 4 knock.