That’s strange, there really ought to be some other signs on the plant if it was anything other than mechanical damage. Other options include plant pests such as insects or slugs but you should be able to see some evidence of them on the plant or on others. Are any of your other plants affected? Tomato hornworms, leaf cutters and beetles will attack pepper plants and will eat holes in the foliage, as will many species of moth or butterfly larvae, slugs or snails but you should be able to find them on the leaves or stems. It’s also unlikely given the time of year; all of these should be overwintering right now.
Are you sure nothing could have torn the leaves accidentally, a pet maybe? Sometimes a dog or a cat will play with the plant and damage it without you realizing.