If it takes 30 minutes for the fuse to blow, it would be doubtful it would be the stator in my opinion. When a stator shorts it typically blows a fuse as soon as the key is turned to the on position. Maybe after the stator warms and there is some expansion, the stator wire could theoretically short to ground, but if it did, I would expect a new fuse to blow right away if you replaced it immediately.
And FWIW, if the regulator failed to regulate and was over charging, that could blow a fuse but other than that a bad regulator shouldn't blow a fuse. I won't go so far as to say it would be impossible, but it would be a real oddity.