Sorry to hear of your dilemma and that you may have a second hog with an injured foot. I know what you mean about the late night stakeouts, you watch out for them all night and then the camera records them ten minutes after you’ve decided to go to bed! All I can tell you is, that last year our camera recorded a young hog that couldn’t bear any weight on his right front leg; it was very upsetting to watch. I knew that he couldn’t have got very far, but when I searched the garden first thing in the morning there was no sign. I searched again when I returned home at lunchtime and spotted a swarm of flies; there just below them about to disappear under a bush was the injured hog. I took him to our local hedgehog friendly vets and he was treated with antibiotics, but the infection had spread to the bone and he could not be saved. The vet said that it was probably just a thorn in his foot that had triggered the infection. I went back through the video footage and just like your hog, he had been showing subtle signs of a limp for at least the previous two weeks, but I hadn’t picked up on it.
Sorry I can’t be of more help, good luck with tonight’s stakeout.