I wouldn't call it pilot error either... other than not knowing just exactly what to do with a crazy unstable snap rolling moster that is....

As Thud Driver said adding more left as a reaction to a right snap is actually the wrong thing to do but it's what most of us would have done in the same situation. What happens is that the added lift of the dowwardly deflected aileron on the right wing made that wing go into an even worse and much more draggy stall than it was in during the snap that yanked the model over in the first place. So in this case aileron was the wrong control to use. Instead a fast application of neutral aileron along with a big shot of left rudder and perhaps a little down elevator may have brought it back under control by unloading the wing and letting it start flying again. But as I said, most of us would have just pulled the left aileron harder and then started to consider other courses of action. But from what you said it was too late by that time.

Just for the hell'uv'it you might want to try this. Find out what the airfoil is supposed to be and make up a little 1/32 plywood template of the first 1/4 of the wing section shape at the tip or a few ribs inward. Use this to check the shape of the leading edges near the tips of both wings. They should be within a thin pencil line of matching that template if you expect the airfoil to perform as promised. If it isn't then it's time to shape it correctly. Remove the high spots and fill in the low spots using the lightweight model or wall filler and reshape until you're eyes are crossed and you can only see a very narrow and even line of light around that template. I may be going overboard here but this is a VERY important spot of your model if you want it to fly well.