who ask him no maintain the house properly?
Not says not maintain properly. Just that he left in a hurry and the landlord says ok. He also ask the landlord to deduct his deposit accorddingly for any cleaning needed to be done. But not until $2000 right?
Ask him for breakdown for wear and tear and ask for proof of receipt. If he doesn't then can take up case to mediation board to resolve dispute.
iciboi is spot on.
Don't think you need a legally binding tenancy agreement to sort out disputes like these.
Both party will have their own risk where there is no binding tenancy agreement filed.
By going through mediation board to resolve dispute also won't help, as you have nothing vaild to support yourself.