Buddy came over and shot with me yesterday. He' s shooting a High Country MaxForce, 63# at 28 inches. Easton 2213 XX75 26 inches with the overdraw. Caliper release off the string under the knock. He had a new string built about two weeks ago and got the bow tuned at the shop. The string is stretching, has about 150 shots through it and he has had to move the sight and peep a couple times. His cams are also out of time now, top cam bottoms slightly before the bottom cam. Now to the question, finally. He shot about 30 arrows into morrel bionic buck and had one arrow hit and bounce off. I was too far to the side to see if the arrow was tailing but it hit the target almost sideways?[] The rest of the arrows shot well and penetration was fine. We checked for vane contact with powder and nothing. Marked the said arrow and it was fine for three or four more shots. Can timing cause this? I' ve never seen an arrow do that before. He said it has happened three or four times since the new string was put on. Any ideas?