The problematic aspect seems to be, that a) Obama was singing the song and b) that there are lots of videos on YouTube of exactly this segment that were not taken down. And in political campaigns there are no automated take downs - just devious acts of sabotage by the opponent ;)

By title? By summary? Surely not by parsing the audio. If automated, why so quick to take down, when there's videos that have been up for years that are the original recordings?

and that is much of the problem - an assumption of guilt based on a spray-and-pray algorithm - and why not, as there's very little downside for a false claim.