So if a picture is worth a thousand words...
The builds on Ryze and Janna pretty much tell everything. Stacking tear and codex? A quick google search turns up a lot of results for these leveling bots, and there is one that uses only Soraka, that is what the poster who mentioned the Soraka must have seen. There is also an auto account creator out there, the author sells it for 20 euros and claims it can solve captchas....
There is a lot of threads on this topic if you do a search. I feel that the OP's suggestion of a report for botting is the best solution, and I've already suggested that in another thread. For some reason Riot removed the option to report for hacking. I've tried reporting them as AFK and in comments writing "farming bot". I've been told by people that they got temp banned for AFKing, so I thought this may get the most attention, but my guess is that it was leavebuster that banned them, and seeing as how these bots are "active" throughout the whole game (would be easier on their team if they weren't, because they feed nonstop), leavebuster would consider them as not being AFK and therefore not ban them.
For now, I'm just not going to play squishies if I'm going for first win in a coop game late at night. Some sadistic person at Riot decided that your enemies in coop games on twisted treeline should all have tons of hard CC, and it doesn't matter how good you are if you get chain CCed by fed bots, if you're squishy you're dead before you can move. I really like Garen for these situations, because he's tanky even if you build him full damage and crit, and his spin-to-win can't be disrupted by anything, and will melt their whole team down if they decide to crowd you while you spin and you've built full crit and dmg and have a level advantage.