Greedo's ability
Refer to these two points from the Rules Reference guide on page 17.
"Appendix 2: Interpreting Cards And Abilities
Timing of Abilities
• If the timing of an ability uses the word “after,” the ability’s effect
resolves immediately after the described timing event.
• Each ability can be resolved once for each instance of its timing
event."
So, Greedo's crew ability would trigger IMMEDIATELY after rolling the dice which is only done once.