I don't know how we could find the insurance information (without expending a lot more in time and resources than any of us here have).
I notice it merely says that he worked as a tower engineer, so it's possible that he was sort of a free-lancer who was employed on an individual basis by those stations (and hence probably covered by their insurance). In other words, possibly he did not go in his capacity as "working for Prometheus Methods," and hence being a contractor or subcontractor, but simply as an individual.
Prometheus Radio Project seems to have been a registered organization of some sort (a non-profit?) in order to accept those grants. I wonder if the "Methods" group was somehow legally part of the "Project."
I realize it's possible that there's no connection between the two groups - perhaps Berg Sr. just knew about the Prometheus Project and wanted to name his business after it as a sort of tribute. Which is still not a very positive sign!
But then again, a global search shows there are two Promethius monikered tower / radio related entities and both of them are associated with Philly. Now what are the chances of that sort of dumb luck? If Promethius were / are working for the enemy, then you can bet that the denial button has been pushed, and both pops as well as the Commie NGO are disclaiming and issuing disinfo in order to throw off the obvious inquiries. I wish them luck if there is any treason afoot here - they'll be nailed for sure if they've done wrong.