I'm not advising anyone to file a false complaint. If he genuinely believes he's being discriminated againstfir whatever reason, he has the right to attempt a remedy by all the avenues open to him under the law. You don't have to like it; he has the right to pursue it whether any non-official thinks he should or not. If he has something, good for him. If there's nothing, then there's nothing.
A smart landlord would certainly see this tenant as agitated (and likely to cause some grief) and offer a month's credit or something similar, a variation of the old "cash for keys" deal, and/or offer a few leads for relocation.
That said, the lease certainly controls, unless for example white tenants who complain always seem to get a pass from the landlord and minorities do not...
Fairfax County addresses the issue at http://www.fairfaxcounty.gov/consumer/tenant/tenan... If he wants to call the Fairfax County Human Rights Commission, he has the right. Let an expert decide the merits.
@Russell Brazil, I don't find it insulting that you believe I'm encouraging him to file a false complaint. I find it insulting that you actually accuse me of doing so and being unethical.
Again, if you're not willing to take the risks of land lording, don't be one. All of my tenants are corporate, precisely because I don't ever want to deal with unpredictable issues like this (valid or not). If you rent to individuals, you must accept that this will happen, no matter how much you may moan about your deductible and premiums.