Several red flags have come up regarding the evidence we've been given.
1. A bullet from a Mauser bolt action .30-06 caliber rifle (the weapon supposedly used) would have caused much more damage to the body than the small hole seen in the neck.
2. Whatever the projectile was, it caused the neck to swell and the t-shirt to bulge, which has been described as caused by a massive cavitation event inside the thorax as the bullet's energy was dissipated outwards. This stopped the heart instantly and explains why the blood didn't pulsate when it came out. A .30-06 bullet would have gone straight through the neck, especially at the angle Tyler Robinson would have fired at.
3. The CCTV footage shows a man running across a rooftop and dropping down to the ground. At one point his shadow disappears. In the background to the right people can be seen appearing out of nowhere and then disappearing, indicating the video has been tampered with.