How often does this happen in these kinds of cases? Lawyers don't work for free and payouts from a hiring suit are unlikely to be all that large (compared to m

How often does this happen in these kinds of cases? Lawyers don't work for free and payouts from a hiring suit are unlikely to be all that large (compared to medical malpractice and the like). I've been at companies hit with employment law cases but always from current or former employees, never from potential applicants. It seems difficult to prove, unless the rejected candidate is given physical proof of wrong-doing.