Amazing how some people here seems always to know better without even knowing the details of the event. I have many PIC hours on the 737 so I am not your newbie you can teach on a forum on how to fly, It was easy to recognize and correct. But it can happen. It also happened on initial approach before LOC capture nowhere near final (that's your wrong assumption) and the hand was on the MCP for just few seconds, enough to develop some asymmetric thrust that was then quickly corrected. Not saying that this is what happened here, just saying that it can happen to anyone.