Could Front Panel/Digitizer part be defective?

I ordered a Front Panel/Digitizer part assembly from this site. I have a friend who fixes these things for a living, he just said if I can get the part, he'll take care of it. Well, I got the part and gave it to him. But, before he put the final adhesive on it, he tried to test it. He couldn't get a touch response around the keyboard area. He checked the cables and made sure everything was proper, then he said the part was defective and "happens all the time."

Any truth to this? Anybody else come into an issue where the digitizer doesn't work when installed?