It is the employer's responsibility, yes. But the argument could easily be made that if the information is in the handbook, he has been notified. There is no requirement than the employer sit down with the employee and spell it out. If the information has been made available to the employee, it's quite unlikely that the employer will be held liable for not fulfilling their responsibility.
Do not interpret this as saying that I think the employer shouldn't do anything more than put it in the handbook. I think a good employer should make certain that the employee knows and understands what his options are. But as far as the legal responsibility goes, if it's in the handbook and the employee has the handbook, the employer has fulfilled it.

