It will cost you 14.99 on tax act and he/she should not pay 200.
I have seen many people with couple kid always file as single and with kid , brings to head of household . That was not a goo advise but .
Last time you said , if a student want to use 1040 instead of 1040 NR and get more refund .

May be this person does not know why he/she wanted to file separately . Being new or someone may have advised like that intending to get EIC on both.