This can happen occasionally on a recurve. Hold riser in non dominant hand and hold the end of the limb firmly in dominant hand and gently rotate in the opposite direction of the twist a few times...not too far, just off center a little bit to where you feel a little resistance. Do this a few times and you should notice it straightened back out. Also, drawing the bow and letting it down is not the same as drawing it and shooting it. If you're torquing your hand on the draw at all this can put a little twist in the limb and cause what you're describing. It's generally harmless but unsettling. If gentle correction like I described doesn't cure it call Dave for further advice. I don't think you need to worry much.