While that may be true, one need only be a citizen to play (in most) little leagues, or to get a passport. Natural born citizen is more than just citizen, and the short form may or may not provide sufficient information to prove that. Add to the fact that Hawaiian ones at leas are easily forged, and you really need to see the original long form certificate, which also had more information, such as parent's birthplaces , to be sure of natural born status.
Only in the imagination of birthers is the parents' birthplace important.
And even if it was, long form BCs only have the birthplace of parents as this information was volunteered by the parents themselves. It states nothing about the parents' citizenship.