Hey, you're calling us out too, because that's our Ford Explorer at the end of Darin's video!
I won't speak for Darin, but my chase partner has experience with being close to violent tornadoes and I trust him completely. We were toeing the line, but we felt safe given what was above us, how fast the storm was moving and what the tornado was doing. There were no power lines on our road and very few trees nearby. The strongest winds we experienced were roughly 80mph from the NW (confirmed by mobile mesonet) which is nothing to take lightly, but RFD or bow echos can easily produce that so they weren't too alarming.
The most important thing is that we felt in control of the situation, and we had multiple escape paths easily available. The storm was moving to the NE, and the tornado eventually hooked north as it lifted as they tend to do. Our road, 175, was perfectly situated to face the tornado and escape to the SW if we needed to.