M.L.
In my experience (as a first grade teacher and a mom), I would say that if the mom and the teacher are giving him adequate attention in other areas, it probably is not a cry for attention. If his needs are met (both emotional as well as academic), he probably truly needs the help.
I have found that allowing children 20-30 minutes of play time when they get home allows them to better focus when it is homework time. In first grade, Homework should only be 10-15 minutes in length. As you near the end of the year, it may build to 20 minutes. If you find that the work is difficult enough to take longer than that, have a talk with the teacher. Also, I would encourage your child to have a snack (or dinner) 15 minutes before any homework time. This will give him a boost of energy for thinking. Also, Mozart has been long documented as having a positive effect on children's performance in school. there is a wonderful CD called "The Mozart Effect". Many teachers use it in classroom. You play it just before any test taking or activities that require major concentration. This music stimulates the brain in such a way that children perform better.
It is possible that the child could have attention deficit, the work is too difficult, eyesight problems, low self-esteem about school, etc. If the problem persists, the mom should have a meeting with the teacher and possibly the pediatrician to rule out other issues.
HTH