"Flung" was for dramatic effect, I'm sure - as a way to say, "I'm too bada$$ to walk it under the tree in the dirt because I'm in the middle of my hooky ride, dammit!" Or, maybe she didn't want to get sand in her cleats. Nonetheless, the battle scars on the cooler from it being flung are character marks - stories to tell next time she's entertaining and the question gets asked.
Looks like a great ride, Asia!! 22 days and counting to Outback!!!