For the record - I had a horse with clear localised flecking around the flanks, he had very little white (a star, that was it) and no white in his tail. He could not have been sabino, he simply did not have enough white... the only options for his colouring are rabicano or simple flecking. His was so localised, rabicano is the only logical explanation.
And yet, no white in his tail, AT ALL. Maybe a white hair here or there but certainly nothing remarkable.
I think it is possible that the OP's horse might be rabicano, HOWEVER, looking at the white on the horse's face, I'm seeing a lot more sabino. Look at that chin spot, there is a pinto pattern causing that, and my money's on sabino.