ETC (read OSIR) has the spill at 146,600 barrels,
or the whole cargo.
Several others repeat this number.
Given the Hooke account, a dwt of 21,378,
and the light density of the cargo,
this is extremely unlikely.
As long as the damage was confined to the bottom,
and the tides were not unfavorable during the 5 hours she was stranded
(probably rising if she refloated herself),
she would have spilled no more than a few percent of her cargo.
Moreover, if there had been any sort of spill,
no way she would have been allowed to berth.