There's a hint that the lag was done INTENTIONALLY by Riot

I had about 3 games including last night in customs, of which me & my friends didn't completed it since we're just testing the lags so the records won't be found in my match history, and so far, I have only noticed that only the winning matches/sides were getting lagged. Here is what I gathered on when the lag settles in:

• usually when im unfed by 1/4, I seem completely fine, being around 200-300 ping, which is considered "fine".
• being the same unfed guy I am, I still went off into the depth of the jungle to help my teammates in there, still around 300 ping.
• got myself 6/4, that's where the trouble sets in. The lag increases til about 600-800 ping for no reason at all.
• got myself a couple of sweet complete items, like full boots & zhonyas, then the lag boosted itself and was jumping around 1200-2000 ping (what the hell....?)
• the biggest rage I have ever felt in my life. Got myself 13/5 in game through a lot of difficulties (my friend is a complete noob, believe me), tand then the ping just raged itself too 5000-6000 ping, completely. Weird part is, after I died, the ping settles itself to 800-1200 ping. It's still laggy, but why that sudden drop? And after I respawned, the ping returned back to 5000-6000 ping, each time when I pressed my right-click.

I dunno, this is just what's in my mind. I could be wrong, could be just my wifi. Hope this relates to anyone's internet speed problems.