Avacados have a bit more carbs than you'd think a high fat veggie like they are, should have, FWIW. Also, some diabetics are sensitive to tomatoes because at least as far as vegetables are concerned, they have a significant portion of calories from fructose (sugar). I can't speculate on the cause, just thought I'd toss a couple of possibilities out there.
Protein can cause an insulin spike as well. It may not be as significant as that of carbohydrates but some people are still sensitive. In order to limit the spike from protein, some people find it helpful to consume higher fat cuts of meat that have lower protein content. And pork chops are pretty lean as far as meats are concerned. For most people this isn't an issue, though some people have reported better success on lower protein levels when trying to control blood sugar.