customer sprayed with msma needs seeded

[DBLC]

one of my customers called to let me know he was ready for lawn to be overseeded. He then stated he didnt need me to spray for weeds as usual, because he already did. I ask what he sprayed and he informed me he used MSMA!!! I know label says wait a month before seeding. He wants to start sooner due to a party next month. What are ur thoughts? Any way to lessen the MSMA affect? He spot sprayed on not blanket but did spray large areas. Thanks for your input!