I honestly wouldn't have said anything about him OCing on his property. But, in the back of my mind, I would be asking myself "why" a person at his own residence, would be carrying a weapon on his hip. Obviously this was VIN check, which are low priority calls. Often people wait a good while for an officer to arrive. So it begs the question, was the OP carrying the entire time, prior to the arrival of the officer, or did he "holster up" to see the officer's response and post it here? Inspection was completed "ten minutes ago" well, what do most people do then? They go to the BMV and submit their paperwork, but apparently this was too good a story not to post up first.
Of course, that is all conjecture. The OP may have very well been doing something else, prior, in which he decided to OC, but for a guy like me who has a hard enough time wearing a shirt and shoes around the house, it does make one wonder.... only wonder though, the fact that he was OCing would tend to make me believe he was law abiding, and thus there not being a need to say anything.
I have my gun on me about 80% of the time, at home. Why would you be suspicious of him just because he was armed?