That is a good point, actually, and relevant I think: If you're on someone's wheel on a climb, watch out for them standing up without warning. If they are not skilled at transitioning from seated to standing on a climb (many people are not), their wheel will appear to move backwards toward you at a frightening rate.

So, 2 things: 1) If you're going to stand on a climb, practice counteracting this backwards motion; and 2) when following, leave a larger than usual gap, unless you know the rider in front of you has mastered #1.