He or she can be, if the person wants to claim it.
It doesn't matter where you were raised, or if you had only one Latin American parent. What really matters is whether you were raised in the culture (or cultures, since Latino culture varies from country to country). However, if you want to claim being Hispanic or half-Hispanic, you may. You have a right to that. It's up to you.
But if you know little of your ancestral cultures, you should make an effort to find out as much as you can.