How long were you driving your truck after it started losing that much coolant?

This is a very BAD thing for these engines. A hole in the front cover will allow your coolant to drain into the oil sump, which can cause rapidly increased wear for the engine internals.

We've seen lots of rocker arm lubrication failures after 100,000 miles, and some attribute it to fuel or coolant in the oil. This needs to get taken care of ASAP! Also, I suggest asking your dealer how much antifreeze made it into your oil.