"MPI found no conclusive evidence to determine that the contamination occurred onsite," she said.
"Laboratory analysis confirmed that the foreign object was a rat foot. However the sample was handled before MPI received it for testing and this compromised the ability of the lab to undertake further analysis to assist with the investigation."
Miss Mosen accepted the foot had been handled and mixed with other food at the time it was served.
"I'm just a bit gutted that they couldn't prove anything."
She was pleased with steps Tegel had taken since and said she had been offered vouchers.
"That's really cool - I'm happy with that," she added.
Tegel said the matter was now closed "both with our consumer and internally".
Miss Mosen said she was unlikely to eat saveloys again.