I have not shot an arrow with a lumenock so I can't give first hand experience. Arrows don't fly straight. Youtube has some good videos of arrows in slow motion. They kinda look like a spagetti noodle in flight. If you are consistantly hitting your mark I don't think that you have anything to worry about. If you notice that the arrow is diving left, right, up, or down then you might be getting contact with a vane. Could be the rest, riser, or even a shirt sleeve, if you wear long sleeves. I would guess that you do hit your mark so don't let it psych you out.
Bowtech Sniper 55lb 29" draw
Easton ST Excell 400 with blazers, 100 grain field point
True ball fire ball release, Octane 7" stabilizer, hostage capture rest, Spot Hogg Hunter sight