Question about listing employment on I-130

[leenkath 7]

My husband (the beneficiary) had an incident at a former job that became messy. It's not worth going into the details of the event, but suffice it to say that an accident happened and his employers got extremely nasty about the insurance claim and, long story short, my husband lost his job in the end. The problem is that my husband is worried about listing this employer on the I-130 because he fears that USCIS will contact them, and the company will say malicious things about him, which will negatively affect the petition. Is that a real possibility?

We both know it is important to be truthful on all forms, and that is of course our intention. But we wonder if anyone has any insight into what kind of checks USCIS does for past employment? Do they just verify the fact that you were employed there? What purpose does this information serve, really?

Thanks in advance.