No, he would not be required to file a New jersey tax return because his gross income was under $10,000. Because Pennsylvania and New Jersey are reciprocal states, he would be able to report the PA income to NJ. He is also below the filing threshold for a federal return, so you would not have to file unless he had federal taxes withheld. He could also file to get a refund of his state withholding if he had any.
See NJ Division of Taxation - Gross Income Tax Overview