Lady Scarlet wanted to make sure that this old slave changed and became well behaved. That is why she had to make sure that he was in a lot of pain. So she crushed him with her boots. She crushed his fingers as well as his head and he cried. He regretted what he had done and he knew that the whole mess was because of him. So he blamed himself for it.
Lady Scarlet needed to teach this guy a lesson and she did it with her rubber boots. The mistress made sure that the guy licked the dirty soles of her boots clean. He had no choice but to do what the mistress wanted. The poor slave wished he had never messed with her but it was too late and he had to endure the punishment she had in store for him.
Lady Scarlet did not want her slave to forget that he was under her instructions and directions. He behaved as if he could do anything he wanted and do it however he wanted. So she sent him a message that he had to do things her way by trampling him with her rubber boots. The slave was shocked and in pain but he got the wake up call he needed.