2001 Chevy Camaro Part Lock Cable

Good evening, I need some help. Back in mid February, I took my car to a Sears Auto Center for some routine preventative maintenance. When I picked up my car from Sears, the car was not as I had left it. I could not get the key out of the ignition once I got home, and at one point, couldn't even turn the key far enough forward to start the car. So after taking it back to Sears and them denying that they had anything to do with it, I took it to a GM dealership to get it fixed. The dealership cited that the problem was a "sticky park brake cable." I told the mechanic at the dealership that I had no problems with the car when I dropped it off and then 3 hours later, this problem arises when I pick up the car. The mechanic at the dealership said that there was residue on the park brake cable (and inside the rubber coating) which was causing the cable to stick. He couldn't tell what exactly was on the cable however. He tried to clean it, but he could only clean the outside, not the inside, so the part was still not good. My question is this: Given the location of the cable (which I don't know enough about) is it likely that Sears spilled something on the cable (or near it) which could have leaked onto the cable, making it stick.

Here is the work Sears completed on my car: Oil change, Coolant flush, power streeing fluid change, brake fluid change, and a fuel injection cleaning. Would any of those jobs be anywhere near any part of the park brake cable? Thanks in advance for your help.

-Ken