Sad discovery, 20m instead of 25.
~0.5s to go 20m = 40m/s
Approximating the stone weight to be ~250g, that equates to ~200J KE.
Still impressive, but not superhuman like before... 

No harm, no foul. Sure makes me feel better though lol.

Impressed at the new rigor being bought to these measurements.

When a figure is calculated on a TV show there is definitely an element of trust that they did it right (and they of course are incentivised to err on the side of bigger numbers for better TV).

Google location deviation.  This system is not always accurate.  I prefer to trust luis.  He is an absolutely confident marksman.

I know luis quite well.
He is probably the hardest throwing target slinger in the world.
He's also 6 foot 4 of hard muscled world class fitness instructor.

He doesn't dial back for target slinging like, well pretty much everybody else.

So if there's any number i would not question it would be the energy imparted by a stone he'd slung. 

I've been hit in the back of the head by a small sea sponge the bastard slung at me from 20 metres - that thing hurt !
I had mini-luis and big luis both targeting me - when there was a much bigger target in the form of gandalf the goth off to one side.

I've also nearly been killed by a lead glande slung at me by larry bray (if he'd got another 3 metres out of the throw, I doubt I'd be here to tell the tale).

I've also been within 10 metres of sling badger when he was slinging (probably the most dangerous sling thing I've done lol).
Even standing directly behind slingbadger is no guarentee you'll be safe.

I'm starting to feel there's a definite pattern here