I thought the wound was in the upper thigh. Any higher would be difficult for someone giving first of aid to apply a tourniquet.
What a strange way for anyone to die.
There were first aid options available. Direct pressure often works. I hope people made some effort to help the guy.
They may have. Contrary to what Hollywood would have us believe belts are crappy tourniquets.
By themselves belts are hard to tighten enough to cut off the arterial blood flow. More pliable material like a tie or shirt sleeve works better. Those materials allow an improvised windlass (like a pen or a stick) to be used to tighten until arterial blood stops flowing. The belt you are just yanking on without mechanical advantage or the good ways to secure the pressure if you do succeed.
Hollywood also wrongly teaches us that you apply belt “tourniquets” over the wound. Like you pointed out in a follow on post, you have to go enough above the wound to make sure you actually stop flow to the damaged portion of the artery. That may not have been an option in this case if the wound was high enough on the leg. It may have an option and the person rendering aid simply followed their action movie lessons learned.
Unfortunately, the real world is not an action movie.
That link appears to be outdated. It was last updated in early Feb of the year (2017) that the Red Cross changed their first aid guidance to include the use of tourniquets.