You should be high left in the lane with a clear sight line to the truck's
left mirror. The car behind you will not attempt a pass as you are
dominating the centerline. You should close up rapidly along the
centerline and wait to cut your right turn behind the truck when you
are sure of its intentions.

The car driver saw an opportunity to pass you because you gave him
too much space.

Lot of assumptions in this post. Maybe the guy didnt see him at all. You could
also get your ass run over while "dominating the center line." Never assume.
This sounds like a road with a lot of space on the right. It is better to ride
a consistent line to the right, where it doesnt matter if you're seen or not,
than to ride left and cut right.

It is better to ride like you're not seen than to ride to be seen. Most of the
time, you can't do both.

Robert