My oil pressure light comes on during heavy braking
This is a fairly normal complaint and usually comes about when someone is practicing panic stops. It's nothing to worry about, unless it stays on for more than a second or two. If your oil pressure light is routinely coming on under normal riding, or stays on for more than a few seconds, you need to find out why. Soon.
This is a moderate engine design flaw. Under heavy braking the oil puddles in the front of the engine cases. There is no easy way for the oil to get back to the pickup at the rear of the engine, causing a momentary pressure loss. This lack of oil pressure can lead to spun rod bearings, especially if repeated often, as on a racetrack.
The best preventative measures are to keep the oil level to the top mark at all times and to use synthetic oil, as it lubricates better when pressure is lost.