The mottling/blotching sure looks like it since its so random and non symmetrical across the leaves.
Its hard to tell without knowing the history of the tree, pesticide use, fertilizer, watering, soil, etc.
Seen any bugs on it? Fertilizing it with micronutrients?
I have had a few trees with HLB and they looked very similar to that, albeit the leaves weren't as yellow and there were other symptoms too.
The disease can only be spread from tree to tree by the psyllid. From what I have read, HLB doesn't seem to be in Hawaii yet (maybe the articles are old?). However you can probably contact your local ag extension or something like this:
http://agrosecurityhawaii.com/new-page if you are worried. You can send them samples or they can come out and take a look. This might be the best course of action to help potentially prevent the spread of disease across Hawaii.
http://gardeningsolutions.ifas.ufl.edu/care/pests-and-diseases/diseases/citrus-greening-faq.html :
"HLB is caused by a bacterium which is transmitted from tree to tree by the Asian citrus psyllid. Psyllids become infected with the HLB bacterium by feeding on an infected tree. When the psyllid moves on to feed on an uninfected tree, the HLB bacterium is transmitted to the uninfected tree. There have also been documented cases of HLB transmitted by grafting, although this form of transmission is far less common.
The movement of infected trees also contributes to the spread of HLB. While the Asian citrus psyllid is the only way the bacterium can be transmitted from tree to tree, moving an infected tree can bring the bacteria into an area where it did not previously exist. From there, the Asian citrus psyllid will be able to spread the disease further."