I am unsure about the phrasing, "pulled," but the net effect will be a turn to the left.

He is right and here is how you can see it. Imagine your in a boat rowing along, you drop the left ore into the water (your reverse thrust), the boat turns left. Similarly if you have a left to right crosswind, the upwind side being the left side, if you drop the reverse thrust on the left engine (putting the ore in the water) the aircraft will turn left, or upwind, assuming it has forward motion when this happens.

Edit: Reverse thrust is nothing more than massively increasing drag on whichever side it is applied, usually both equally, just like dropping an ore in the water massively increases drag on that side of the boat.

Make sense?

Sorry for the triple posts by the way, just saw this.