how to flush

Not trying to promote undue fear, how long do you suspect it was leaking? Was the oil thickened as a result? The reason I bring this up is that coolant in the lube has the ability to strip the outer (softer) materials from the bearing face.
If this was to the point the oil was thick, I would certainly think about pulling the pan for rod/main inspection.
Good luck, hope it shakes out in your favor.