This unit does indeed have split OCP, but as far as I know, exceeding the trip point should cause the PSU to power down, not reset the PC (unless the PSU manufacturer did something
really strange with the protection circuits).
But according to
this site, the thermal design power for an 8800GT is 125W - a little over 10A worth. I assume that the "24-28A" number you reference is some recommendation for the
total output from the 12V rail, with some margin in an attempt to compensate for dishonestly rated PSUs.
By the way…
70a = dead graphics card!
The PSU isn't always delivering its rated output. It delivers as much current as the loads demand - no more, no less.
If it followed that common misconception, then nothing to do with electricity would work correctly. Power circuits feeding outlets in most buildings have capacity between 10 and 20 amps but few appliances actually require an entire circuit worth of current (and in Australia, practically none as we usually have 16A power circuits, but normal outlets here are rated for a maximum of 10A each).
If you're not convinced, then look up Ohm's Law and come back when you're done…