Knitter's Dilemma

Today at work I asked another specialist to assess one of my patients. As we were discussing his findings, his sweater caught my eye. It was machine knit, but had some unusual detailing. Then I realized that the "detailing" was stranding. His sweater was probably on inside out. Because he was sitting and I was standing, I was able to walk behind him and check to see if there were any tags visible. I didn't see one, but I thought I saw a bit of thread where the tag might be (what you would expect to see if you removed a scratchy tag from your sweater). Now it's possible that this was a somewhat edgy sweater, but his style is anything but edgy. The "motifs" were quite small, and the yarn was a fine gauge. I doubt a non-knitter would have noticed. So my dilemma was this - should I have said to him "You might want to check your sweater, because it may be inside out", or just let him continue on in blissful ignorance?