New deck/stain over-applied to half- how to fix?

I live in Maryland just north of Rockville. We had our deck rebuilt with new deck boards of pressure treated pine. They were dried for almost a month after installation before staining. We had the contractor stain the deck with semi-transparent Olympic Maximum Stain-Sealant in One. When they applied the stain, they did it in the shade on the first half, then apparently stained the second half in the sun and kept going over that side to even out the color on the second half, leaving a very dark/blotchy deck on that side totally different than the correct color on the first half. We suspect the stain was drying very fast in the sun causing the problem.

We are at a loss on how to get this corrected. Since the stain that is down is only a few weeks old, we are unsure if any of the recommendations for older deck restoration, etc. would apply here. Applying more stain or even going to a opaque product like Deckover would seem to leave us open to peeling and loose the look we achieved on the first half that was correctly stained.

What would you recommend we do to get an even stain across the deck? Our contractor seems mystified as to what happened.

Thanks advance.
Paul