Perhaps RWA summed it up best [at post 104]:
Maybe the cab driver was a friend who was waiting nearby.
Either that or a critical juncture on a major thoroughfare fell victim to a 4 AM manifestation of Murphy's Law while the lucky truck driver hailed a convenient cab.
To clarify, I saw a later report that said the guy went to a nearby gas station and called a cab. That would make it look less planned. So, someone reported wrong, but I’m not sure who. I guess it reinforces the danger of speculating based on early reports.
You would think he would call the cops or an ambulance, but maybe he only trusts cab drivers.