Scary oil change

So I'm pottering around with that old XT500 I bought. Didn't want to start it before I'd changed the oil and checked the oil lines weren't gummed up as it's been sitting for at least 7 years (so the bloke told me). He also told me he rode it up the drive when he laid it up.
So WHY when I drained the sump filter and frame tank (it's dry sump) did I get about HALF A LITRE OF BLOODY WATER COME OUT!?
Can't believe that it's condensation so I suspect that he drowned it off-roading out on the Plain, towed it back then shoved in the shed.
Any other suggestions before I go round and give him a slap?

OK, just let me have your address mate and I'll hire a van. Do you want a go on my Mrs as well?

Nah, I'm quite enjoying fiddling with it. The rockers look oily and the feed lines are clear so probably no damage done. We'll see when I can wrestle the carb back on.

Supertedlover wrote: Give him a slap. Go on. Have you had a camera in the crank?

Nah mate.
I'll 'audio' test it. If it's damaged it's already done. Won't take long to strip if it sounds bad.
Already owe him one slap as he hasn't given me the log book yet - says it's 'somewhere in the back of his garage'.

Bit of water won't do it any harm  few years ago I bought a CBR125RR for my daughter off this little scrote for peanuts as he'd lost control on a bend, ridden across a grass verge & into a river  Stripped the engine down which was completely full of water, cleaned it up, put it back together, ran perfect. Water had only been in it for a week though