I had a real live experience with someone's failure to distinguish between the two, right here on APUG. I posted an image of a solo male nude, with dramatic lighting, no signs of arousal anywhere in sight, and no sexual activity solo or otherwise transpiring in the image. Someone seeing it determined for themselves that "sodomy" was transpiring in this photo. It takes a rather fertile imagination to get from one flaccid penis to an act of penetration. But somehow this individual did.
I you see my definition of "Porn" as I grew up with in Missouri - the depiction of a primary sexual organ might have done it. Not sure where sodomy came in - but perhaps the definition needs to expand to any depiction of males in any sexual way might be considered homoerotic...?
B & D Rochester, NY
======================== Quiquid Latine dictum sit altum viditur