Okay, I am posting this to make sure I am doing things correct. @TAXOH @IRonMaN .

To be Head of Household you have to have a qualifying child (you don't have to claim that child that is why there is place under HOH to enter the child's name, SS number).  Be unmarried or lived apart over half the year (they are unmarried).  You have to have paid over half the cost of keeping up the home (I am making the assumption here that he paying over half the cost of the home but that is not clear from the items posted so far).  It appears that he meets all the criteria assuming that he did provide of half of the support.

To claim the child it appears that all the criteria are met.  
qualifying child - check
member of household - check
age test - check
support test - child did not provide over half of their own support - check

So the child can be a qualifying child of either parent so either can choose to claim the child if they both agree.  If they don't agree then the tiebreaker is the higher income.

This is covered in The Tax Book on Page 3-11 the 8th one down.

Dusty Ernie