UPDATE: Yesterday I went back to the dealership and pointed that I've found out this is a known issue with numerous Explorer owners and asked him to check for a "TSB" (Technical Service Bulletin) and low and behold there was one!!!

He was surprised and couldn't figure out why the tech didn't check for this while the vehicle was in the shop. He printed me a copy of said bulletin
SSM 44564 - 2011-2014 Explorer, Taurus, Flex, Edge, MKT, MKS Workshop Manual Updates for Rear Brake Service
Some 2011-2014MY Explorer/Taurus/Flex/Edge/MKX/MKT/MKS vehicles may exhibit a rear brake drag condition due to corrosion build-up between the brake pad and anchor bracket. Verify that the brake pads and anchor bracket are free from corrosion or debris and that they slide with minimal resistance. Use the Rear Caliper Piston Adjuster tool per Workshop manual section 206-04 to compress the piston and verify it is moving freely and not the cause of the brake drag. A moderate to heavy force the caliper piston must be applied. If sufficient force is not applied, the internal park brake mechanism clutch cone will not engage and the piston will not compress. Make sure the piston notch is aligned with the pad pin, or caliper drag will result. Please reference the online workshop manuals for the latest repair information.
I'm going to request that they service the front brakes for not doing their job and the inconvenience they've cause me.
Thanks [MENTION=157968]FordService[/MENTION] I appreciate the offer but I think I've got it from here. I'll try to keep everyone updated.