Looks to me like he inverted it, but you should still be sure to glue the tabs on the inside either way so you can sand it down easier and know exactly where your creases are for the detailing stage.
yea you need to redo it glueing the tabs on the outside thats proabbly what caused the warping, and only mold it when your absotlutly sure its the best you can do cause molding is really expensive
True the tabs on the outside doesn't really help the shape but good effort on trying a HD file. You can carry on i guess but you would have more work involved ^^. Keep it going Nice to see more Marines.