Living in the farmhouse that A helped to find, Aaron would naturally know Yang Yi's location.
So, on the second morning after Yang Yi moved into the farmhouse, while he was having breakfast, a stranger placed a folder on his dining table.
"This is for you."
After placing the folder down, the man who delivered it said with a stern face, "This is evidence."
Yang Yi, made somewhat paranoid by Cupid's ruse, was immediately relieved.
Having Aaron look for evidence, the speed was quite good. It was delivered in just two days, quite efficient.
Yang Yi opened the folder and pulled out a stack of papers, all paper documents, not photos; there were no pictures in the entire file, only lists of financial transactions between bank accounts.
The most direct evidence would of course be photos or videos, but the chance of Nicholas being caught on camera or recorded while doing something secretive was almost nil, even Aaron couldn't obtain such evidence.