Absolutely not; total waste of lube. Don't change it.
Considering that it was used under full load for the 12 hours (or at least a large portion of it), there's likely no moisture in the oil.
I have run 3 to 4 years for my OCIs in my Kubotas, up to 150 hours. Never had an issue whatsoever and the UOAs showed good wear traits. When I cut the filters open, they were perfectly fine also.