Is this boss out of line? Is it fair to blame a subordinate and not the reviewer in this case?

A boss pulled his subordinate up for an error made in data entry even though the employee's supervisor had reviewed this, signed off on it and not identified the error. The fact is, the employee has many data entries to do and even though they take care for accuracy, due to human error, the review is necessary for checking, identifying errors and signing off. The employee pointed this out to him, and explained that they can't be responsible for 100% accuracy due to human error and that the supervisor should be pulled up on this matter. He disagreed with the employee. The employee then told him that they would take responsibility, sign off if he let them do the review of their own work, but indicated that they feel it is better to have another person do this as it might identify something that they can't. Is this boss bullying his employee? Isn't it the reviewer's role to identify errors given that there are hundreds of date entries done and that in general the employee has a very good work ethic and low error rate? Doesn't the buck stop with the reviewer/ ie. the signer especially when the subordinate has a good track record?