Probably plenty of truck.
Just too much tail wagging the dog!
Or too much golf cart, slinging the tail, which rolled over the dog.
This nearly happened to my dad when I was a kid. He was bringing home my brother's Firebird on a big Uhaul car carrier behind our Econoline. Turns out the surge brake controller was completely useless. Long downhill, he couldn't slow it down. Trailer was pulling him across all 4 lanes, and actually dented both sides of the van's bumper. But he rode it down, braking hard only when the trailer was directly behind him. Changed his shorts and limped home.
thebrakeman ('70), DW ('71), DD ('99), DD ('01), DD ('05)
2004 Surveyor SV261T (UltraLite Bunkhouse Hybrid)
2006 Mercury Mountaineer V8 AWD Premier
Equal-i-zer WDH (10k), Prodigy Brake Controller