The Interaction between Ashe's and Infinity Edge's Passives

I have been away from LoL for a while, just recently coming back. In that time the marksman items had changed majorly. While I was getting accustomed to these changes, reading the descriptions, and noticing the new Infinity Edge, particularly the true damage passive.

My first thought was on how it would effect Ashe's passive. My original thought was that the passive would boost Ashe's passive and deal true damage with every shot after the first. When I tested the build, I found that the passives don't mix. My confusion was over how the item passive wouldn't work with Ashe's passive, considering how Ashe doesn't crit like all other champions, every strike after the first being boosted by crit chance.

Does anyone have any idea on this situation.