That's the kind of work that makes me very suspicious of who was working and running the job.
I looked into using I-joist on a job once and it was cost prohibitive compared to a truss system on the labor side. I have yet to see anyone around here using them on a typical load roof set-up.
From the picture it looks like they would have needed to move the B-vent over about an inch to not cut the I-joist. So much for a project management or thinking carpenters.

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Accurate Inspections & Consulting, Inc.
773/844-4AIC
Markus Keller