I recorded a little video with my cell phone this afternoon to send to my Mom, and she called me after watching it and said, "Did he say mama?" It happens near the beginning, right after I say "Hey, baby". It sounds very clearly like "mama", though his lips aren't synched with it on the video. I didn't notice it at the time, and I can't help but think it was just a glitch.
Watch and decide for yourself:
What do YOU think? :-D