How do you arrive at 700 pounds at the edge? Take one joist, assuming the joists are 16 inches on centers. Assume two people are standing back to front at the rail, at say 175 pounds per person. That’s 350 pounds on one joist, over an area of 2.67 square feet, incidentally a load of about 130 PSF. The load isn’t all at the very edge, so let’s say its assumed to be at 12 inches from the beam. If the “main span” is 16 inches, then the uplift at the inside end of the joist is 350 x 16 / 24 = 233 pounds.
All of Simpson’s face-mount joist hangers are capable of resisting at least that much uplift, and most will resist many times more, as can be seen here: http://www.strongtie.com/ftp/catalogs/c-2008/C-2008-p082.pdf
There is nothing wrong with the deck pictured, as long as the hangers are fully nailed as specified by the manufacturer.