Gary, so sorry to hear about your losses.
I assume you mean the SG was 1.015? That's roughly what the math works out to.
This is exactly why I "preach" redundancy all the time, and so many people ignore it, or plan a future resolve. Most of the time they sneak by without any problems (which encourages others to walk the line), but the unlucky ones like you get dragged through the flames.
Your RO/DI reservoir was 37.5% of the system volume. One of my "redundancy rules" is that an ATO reservoir is never more than 10% of the system volume (and never, ever, EVER attached to an RO/DI system which provides an unlimited supply of RO/DI). A full 10% addition of RO will reduce salinity from 1.026 to 1.024 which isn't enough of a change to affect most corals - even SPS. Something to consider for your future tank, so even if the reactor (or something else) failed and dumped system water out, the salinity wouldn't drop too far.
I have one of your SPS, I'd happily send you a big frag when you're ready.