Can an Action card's 'when your Space Marine slays a Genestealer' ability trigger during the Event phase?

Question

Accepted Answer

Yes, for abilities that last the whole round. Such an ability can trigger outside the Action phase, once per round, if its card was played that round. A reply relaying a designer confirmation says so, and an earlier reply that said no was superseded.

Space Hulk: Death Angel – The Card Game

Can an Action card's 'when your Space Marine slays a Genestealer' ability trigger during the Event phase?