Answer:
Falsely inflating appraisals
Explanation:
As seen from the scenario, as Mike and Tim are friends, Tim tends to increase the appraisals for houses which are being flipped by Mike. This is an illegal activity as discrimination is being made and more money is taken from the customers than actually should be taken. Both are looking for their benefits and hence, tend to engage in a kind of illegal activity. Tim should have kept been fair in raising the appraisals.