Even what is written doesn't sound lawsuit worthy. In the end, the company was offering an existing employee a raise to $50K per year and this one unrelated guy thought $60K was a better offer. It's a fine line. I can't see the guy winning his suit based on only $10K difference to an employee that doesn't even know this conversation is happening.
Companies are always trying to pay less than they have to, regardless of race. I've seen countless times employers being happy that a candidate, when asked how much salary they wanted, came back with a low number. Everyone in the hiring process knows the candidate is under-pricing themselves to the market, but lo and behold the offer comes at what they asked for. "More money to get the next candidate"