Yes, you can file without the Form 1099. It is possible, however, that his 11 hours of PFL were included in his W-2 wages.
If a 1099 was issued and you never got it, the IRS may send you an automated Notice of Proposed Increase in Taxes later this year.
They will calculate the tax due (plus interest and penalties) and you can send them a check (no amended return necessary).
It is extremely common to omit reporting a Form 1099. You file before they arrive, they get lost in the mail, get lost in your house or get tossed along with junk mail.