Considering the skydiver also has a significant speed, that corresponds reasonably well with your estimate.
The rock also looks very much like fragment of a meteorite with classic "fusion crust".
And probably they would have known if an airliner was in the area, considering they were essentially right above a general aviation airport. And probably airliners would not choose to fly over that area.
I think the meteorite identification is much more plausible than anything else.
Considering the skydiver also has a significant speed, that corresponds reasonably well with your estimate.
The rock also looks very much like fragment of a meteorite with classic "fusion crust".
And probably they would have known if an airliner was in the area, considering they were essentially right above a general aviation airport. And probably airliners would not choose to fly over that area.
I think the meteorite identification is much more plausible than anything else.