But they did try to hide it. It's in some videos where one of them was trying not to admit they were remotely controlled and that "probably some AI is used"
I think "AI" did control their walking. Although calling that AI is probably a stretch.
Nobody reasonable considers ifs and dependency injection to be AI.
I find it incredibly silly that 20+ years after the first more advanced "AIs" in games like Half Life, we're still far from a point where I can fire up a game of Dota 2 with bots and have the bots behave constantly well at an intermediate level, so that I can turn Dota 2 into a solid single player experience (I don't have the time nor the patience, anymore, for managing a team of toddler brains for 30-60 minutes).