One of my truck drivers had some similar happen to him at a paper mill. He was siting in line because something was down inside the mill, so the driver ahead of him decided to come back at a different time. In getting out of line and jockeying his truck around, he backed into my truck drivers truck. The overhanging wood (8 feet of overhang is allowed by law here), pierced his window, then went through his cab, and finally hit the headache rack behind him. Only when it did that did the truck driver that hit him, realize that he was spinning and something was amiss. He saw it coming though and was able to flatten out across the seat and was saved from being hit. That was at a slow speed though, I imagine ramming into another truck headlong at a stop is another thing altogether.
That has always been a fear when I see those longer logs being hauled. Just as bad as a log falling off and then going through a windshield. Wood and trees are our friends but we must always remember they can do damage too.
I'm most unsettled by the way phone poles are transported locally. Just an accident waiting to happen.
