A little knowledge is a dangerous thing of course, however...
...Don't see how you can discount Vortex Ring, whether inadvertant (ie met induced) or not. We're not all American, so you can ease off on the "more correct" terms!
My concerns are more with the fact that the NTSB report highlights how many other aircraft were prepared to violate their minima to continue their tours. 100ft with fee-paying pax?! Mama mia - you'd better have a good reason for that versus doing a 180deg turn and saying sorry folks, the ride's over.
Was this a single-engine Squirrel? If so, the odds are massively against making any of the so-called suitable areas if the donkey stops. Did the pax have lifejackets for a prolonged flight over the water? Is the industry so focussed on the bottom line that it's prepared to put lives at stake. Does anyone in the safety chain care?