Becoming clogged is the worst case scenario, and many people envision a clogged drain in a sink as being what they are comparing this too. It actually only takes a small piece of trash like some gasket sealer or a piece of gasket to stick into the valve preventing it from closing fully and oil is bypassed at this point because the valve is only partially closed/open. This is very common on freshly rebuilt engines where you have a lot of break-in going on and a lot of left over stuff getting into the engine. You'll probably be ok.
