I wouldn't worry about it. It isn't even close to done. Briskets and butts always go up really quickly in temperature in the beginning, and everyone panics if it is their first one. You will probably find that your temps will stay put, or even drop a little at some point. The point and the flat temps will eventually read closer to the same. Go by whichever probe reaches it's temperature last (for example, when both probes reach 195 or higher). I like 195 in the flat, and 205 in the point. Don't panic and open the door anytime before that. You will be surprised how the temperature practically stands still. You can rest assured that at 225, your 14 lb brisket still has a long way to go.