Sounds like you'd be open to believing that he got the shot if the test came back positive. I just get the impression that others would question if it was his blood that was tested, or whether the machine hadn't been tampered with, etc. Unfortunately it's not something that can be proven simply with one's own eyes.
What would constitute proof in this case? A piece of paper that can be forged? Even a video of him receiving the jab could just be saline.
Independent lab tests of his video taped blood draw revealing spike protein in his blood would do it for me.
Sounds like you'd be open to believing that he got the shot if the test came back positive. I just get the impression that others would question if it was his blood that was tested, or whether the machine hadn't been tampered with, etc. Unfortunately it's not something that can be proven simply with one's own eyes.