So, our lawyer just got off the phone with cs office, and it turns out that the mother has been collecting welfare in dss's name for a year. She claimed to be the custodial parent and that we had him 9% of the time (we have him 80% on paper, but more irl). She's been caught, so she's freaking out at dss, but even if he did spend everynight with her that he is supposed to, it wouldn't add up to what she's claimed. She also has visitation of two other kids, so I assume she's been collecting on them, too.
I hope something good can come of this.