^ For starters, I imagine the song is pretty hard for them to sing well live. Performing dozens of takes in the studio makes it possible to piece together something that sounds good in English, but doing it live exponentially increases the chances that one or more of the girls will screw up their pronunciation. Even when you "know" how to say something in a foreign language, if you're nervous, you can find yourself reverting back to your bad native pronunciation.
Also, I don't think their lip sync was bad. I think there was a problem with that upload. The interview+perf. upload lip sync looks much better imo.
Also, Harunyan. <3