Funjets use a high Kv motor and are very high pitched and loud. Maybe that had something to do with the attack or ? If it was an osprey and they are fish eating birds, was this near water that the attack happened?
I had an encounter w/ a falcon years ago while slope soaring on a small bluff during a windy stormy winter day. It was blowing about 20 mph straight in and I was having a lot of fun flying a shrike, a 56" fast and maneuverable wingeron, when out of nowhere I hear ppsssrrrrrrrrrrrr, and I see it diving at my plane, talons out! Instinctively, (read-not thinking) I dove as well, rolling and pulling up elevator here and there trying to shake him, which I couldn't, and almost wreaked while trying to do so. I calmed down a little but he was staying just a foot or two on my tail. I tried doing a split S, but as I dived he'd just tuck in his wings, and as I pulled up he spread out his wings, staying right on my tail. As I did my half roll and pulled on the elevator, he'd back off for a second, then with a flick of his wings, he dived down and got right back on me. When I tried a half cuban 8 by diving down, pulling up inverted, then doing a half roll, it threw him off for a few seconds, but he'd just flap and get right back on me. Finally he got bored and left.
Below is a cool video w/ some great FPV footage as well. The fun starts about 1:20