Yes, where did it come from?
I have limited knowledge (says OH) about WW2 barrage balloons, except they were over major cities, towns and other important sites, such as docks, but I've not heard previous local comment about barrage balloons. At that time, approximately autumn 1944, I believe they were rearranged to be more of a barrier to the V1's., along the southern fringes of London, as the last line of defence if one had survived interception over the Channel, AA on the coast, more fighters inland and then the balloons.
It doesn't seem likely though that a balloon could have drifted so far south, and there are HT lines and pylons south of the Rec, so it may well have come from the north....
Just more examples of the misfortunes of war, one brave lad trying to stop a balloon (he did have a crowd of other kids to start with, but as the balloon drifted, so it shed more and more until he was the only one left) and presumably by then too high to safely let go.
Then a V1 narrowly misses the village, presumably brought don by a proximity fused AA shell and explodes; just as the funeral service ended, and a few days later th tempest crashed on the outskirts, attributed to being hit by our own AA fire (probably another proximity fuse) as he closed on a V1...
Presumably no one thought that a proximity fuse would also down anything it came close to, they were maximising their ability to shoot V1's down.
Hopefully Doc and Nurse 42C are getting Skip kitted up ready for Ops?..........