How the Frequency???

So on Sunday, I was at a mostly traditional shoot at Long Hammock, which is out in Oxford, FL (northern end of Sumter county, just slightly south of Marion County) and I had what must've been one of the weirdest shots I ever took. I was standing about a chain (22 yards) from the target and took a shot and hit the plastic easter egg that was hanging on the target (see diagram below). Instead of penetrating the egg or deflecting to the side and hitting somewhere else on the target, my arrow flips end over end straight up and over the target. The easter egg (attached by fishing line tied to a piece of Serenoa repens stem serving as a stake on the other side of the target) also flies straight up and goes behind the target, at least the top half (attached to the string) does. The bottom half falls off, revealing some chalk and a prize for me :)

If this had been something like a 30 lb children's fiberglass bow with kiddie arrows with the rounded crimped-on points from 40 yards, I could see this happening because the shooter would have to lob the arrow into the target... But this is from a 56 lb @ 28" static-tip hybrid bow with a fairly heavy arrow with a sharp field point, a fairly strong front-of-center... and at a fairly short distance and a very straight trajectory. Any ideas what might've happened? There's several baffled archers (including a few with a relatively solid physics background compared to your typical Long Hammock shooter) that are trying to figure this out!