It is one of the most troubling pieces along with the spot in Filomena's with both Amanda's and Meredith's DNA. I think it is possible that he touched it while it was on the drying rack or maybe when it fell off. I doubt the DNA came from being on the floor but more likely from tertiary transfer from the door knob for example when the ICSI entered the room and touched the clasp.
It could have been planted in the usual incompetent PLE fashion containing multiple profiles.
Is it possible that after Amanda showered and walked barefoot throughout the house, she could have picked up some of Meredith's blood on the soles of her feet that had beed tracked outside the room by Rudy and then after entering Filomenas room to see the broken window, etc she stepped on a piece of the minute broken glass particles which caused her blood/DNA & Meredith's to end up together in Filomenas room?
How many facts do I have incorrect in this scenario?