You know what, getting significant oil in the brake fluid, is going to be noticed quickly, if anything happens at all. So if it has not done anything in a week of time to the system, then nothing untoward is going to happen months forward in the future. Common sense should prevail, not panicky feelings. I go by what the thread starter SAID, and said it was an ounce, meaning a small top off of the reservoir was done. IT WILL NOT MIX, suck it out and refill with brake fluid. Better to do that, then do it again in a day than flushing the whole system. If you flush it down then your certain to get some ATF going into the system. Suck it out, use a paper towel dry it out, then refill.