Something has caused the feet to die and fall off, similar to what has been described in the tail docking post. My guess would be that the heating pad was too hot for the baby tortoise. If this were something new, for example a rat chewing them off, there would be blood and an open wound on the legs. This is a very old injury that took a long time to happen, and while it was happening, the leg portion of the injury had time to heal.
I'm sorry this happened to your RF tortoise, but there's nothing you can do about it at this time. I suggest you remove the heating pad and use overhead heat instead.
I'm sorry this happened to your RF tortoise, but there's nothing you can do about it at this time. I suggest you remove the heating pad and use overhead heat instead.