I think Brad is afraid that the DNA test will rule out Shiloh as the father, but also show it’s actually Michael. That would be assuming that Michael’s DNA is on file somewhere and they run Wiley’s DNA against a database. Michael did spend time in prison, so I suppose it’s likely his DNA is on file. Nelle’s probably is too.
On another note, can someone please just kill Shiloh? He’s horrid and I’m sick of him!