Guild Wars 2

I was just wondering i fought a mesmer a couple of times, and i got hit by moa form,
and as i was running from this guy he immobilised me and then blurred frenzy me
i thought “oh great im dead” then poof i stealthed and still got hit but it dropped moa form

the spec i run atm is 0/0/30/30/10 and i was wondering if the ability last refuge which stealths me if i drop to 25% health was overiding moa form.

it seemed as to happen more than once as well. working as intended or bug? to put it more cleary a 5 point trait may just save our kitten?

Edit:
Sounds like you dropped below 25%, which triggered Last Refuge, then because you were in stealth Shadow’s Embrace triggered and removed moa.