This is somewhat hard to follow but I think what you're saying is that your business partner filed a personal articles insurance claim and they ran a loss history report on your partner when applying for insurance on this duplex?
Is the duplex owned by an entity or partnership of individuals or...?
Many companies when applying for a dwelling policy will run an insurance score and loss history report (CLUE report) on an individual in control of the entity even if the policy will be in the name of a business. Apparently, State Farm is declining coverage for one unrelated claim which is quite hilarious but perhaps there are unsaid reasons for that or other past claims.
Anyway, if you apply for the insurance either as the individual named insured or as the person in control of the entity the claim your partner had would never come up. That said, depending on the carrier, the pricing might be different with you as the insured vs. your partner if the carrier uses insurance scoring.