There's a difference between a bot that's been programmed to act intelligently and a bot with superhuman abilities and reflexes. You can have the first part without the second.
Any source for this? I refuse to believe it.
With superhuman reflexes, a bot can be nearly immune to skillshots in a 1-on-1 scenario. A bot can also always hit skillshots, up to its accuracy of prediction of your movement, and your reflexes in dodging.
In theory, a team of humans might demonstrate better teamwork, communication, and adaptation than a team of 5 AI. However, given how much of the game depends on mechanical 1v1 conflicts, I'd expect a simple bot to beat even the most expert human players.