Buying Subject to a Lease, which is being Violated

[Darlene Oliver]

I am doing due diligence on a triplex in DE.  One unit is rented. Its lease has been provided, and the standard real estate contract states that the sale is subject to this lease. 

The tenant has at least 2 additional people living there and a dog, too - three violations. When I mention that  the seller needs to cure the violations, the agent replies that the tenants pay on time and the seller is not going to "rock the boat" with paying tenants. Seller is not providing proof that the tenants are paying and paying on time. Top it off with the seller being an attorney, which the agent uses in attempts to intimidate me into dropping my concerns. 

What recourse do I have? The agent says loudly that I will lose my deposit if i do not close.  All comments appreciated!