Can Sharing a pillow case case a false positive hair drug test?

Hi,

My fiance had a pre-employment drug test. The urine came back clear for everything, but the hair test showed trace amounts of Oxycodone and we are trying to figure out why. He absolutly does not take drugs. I however have had several prescriptions for percocet in the past few months. I had 2 presctiptions about 8 months ago after my C-section, and Had another 2 prescriptions after having a botched wisdom tooth extraction about 4 months ago. Obviously these drugs would show in my hair. We share pillows in bed, and I also have a thyroid problem so a lot of my hair comes out. I'm wondering if this could be the result of his positive test, because we can not think of any other possibilities.

So I'm wondering if I sweat or my hair comes in contact with his hair every night could that be a possibility.

Thanks so much

*****Please do not answer if your going to say he took the pills....That's not what I want to know. I strictly want to know the answer to the specific question asked! Thank you!!!