How would you prove that an opponent is hacking/cheating/scripting/etc.?

Just lost an Irelia jungle round where I am reasonably certain that the enemy team was using maphacks. They didn't ward at all, as I had Raptor buff as often as I could and didn't detect wards, but would constantly get 4-5 man ambushes on me and my teammates, regardless that our areas were clear of wards. Additionally, whenever I would enter my jungle, unless they were ambushing a teammate, they would always ambush me in seconds. And no, it's not a coincidence, as they were always, 100% of the time, on the correct side of the jungle to intercept me. To do that, you would have to always see which path out of my base I take, which is impossible without cheats.

I'd go on, but I'm sure people are just going to side with the cheaters, so back to the topic's purpose.

If you knew someone on the enemy team was cheating, using scripts, etc., how would you prove it?