Bohadschia certainly needs more work. We now have a pretty good idea about the Pacific spp., but the Indian and Red Sea spp. need more attention.
Chantal, is there a ventral shot of this beast? The photographed specimen resembles a form reported from Sri Lanka. Please see attached photo sent by Chamari last year. I believe there was another record of this form from the Indian Ocean, but I could not find the specific email. This form certainly resembles the argus X vitiensis hybrid, but details appear quite different from the argus X vitiensis hybrid. For argus X vitiensis hybrid, the bodywall coloration is uniformly that of vitiensis, either brown or cream on both dorsum and ventrum. Plus, the spots for hybrids are uniform in size.
As Gustav would say, a tissue sample and voucher specimen could tell us much about this form..