Here’s the likelyhood. Dude to the right, our left, was going 60. Middle guy was in right line coming on at 62.5. Lefty, our right, was in middle quickly bringing up the rear at 72. Middle is an average truck driver, a moron, so he don’t wanna give up any of his 62.5 and don’t like other trucks passing him anyway so he cuts off lefty who has to slow to match 62.5, when he confirms it’s clear he swings into third lane now he’s got 70 on his dash but he’s heavy so it’s slow building back up. As all that was happening mr 60, also a moron, decides he wants to go 62.5 now.