Doesn't sound like much proof to me. I don't blame ya for not turning him in. You only heard a shot, then saw a deer next day?
I myself have to be sure before turning someone in. People don't realize the effect it could have one people's life if they are wrong. Me for instance. Three years ago, I was bowhunting during the muzzleloader season for does. So there was a muzzleload shot down the hill from me. A doe I figured. Never saw it. A few min later, I shot a 5 pt buck. I see my neighbor starring at me, thinking I shot it and she didn't realize it was doe muzzleloader season. Talked to the DNR, they looked at the animal and said, no problem.
But it was a problem. Caused me several days of problem in the line of work I do. I was going thru a security clearance and had to report the incident. That led to long talk with anther investigator. It was cleared, but was uncalled for. And all because the ignorance of a lady making assumptions.
People don't realize what they are doing to others if they don't have proof.