If all that is stated is true, then yes, I would say the tenant has a legal claim against the landlord. However, it is common for month to month tenancies to be documented nowadays as well. Therefore, the lawyer must see the underlying contract if there is any. For example, the poster states that the landlord had 30 days to take this action--is that because the contract gives the landlord 30 days? or something else? In other words, what is "valid" in these situations is highly dependent on the underlying tenancy contract.