Earlier quoted context omitted.
"Under the FMLA, most new parents can take up to 12 weeks of unpaid leave without the threat of job loss. That’s most parents, not all parents. Employees qualify for leave under the FMLA when they’ve worked 1,240 hours over 12 months at a company that employs more than 50 people. With part-time workers and small business employees left in the lurch, only about 60 percent of American workers are entitled to leave unde…
Not to mention that with at-will employment this is essentially a moot point. If you qualify for FMLA and take paternal leave, they can still just fire you "just because we felt like it".
It's not like criminal law where violations have to be proved beyond a reasonable doubt, so merely presenting a plausible alternative consistent with (even if not the most likely conclusion from) the evidence is adequate to avoid liability.