Well, technically, if the guy was a white guy that went down there specifically to kill hispanics, it was racially based terrorism.
Fortunately that doesn’t happen very often, but it is always a risk in a multi-racial culture. There are always a few guys out there that are one short of a sixpack.
It’s OK to label someone as a “white terrorist” but wrong to point out if a terrorist is muslim, black, etc.
If one of the Mexican drug cartels killed some people and we called them Hispanic Terrorists, they would have fits.