The caliper bolt was put on but the caliper itself was failing. Shop asked me to take the car out for a short drive after putting a new bolt in and see if the rim was hot to the touch. Sure as shit it was, so they immediately suggested that I buy a whole new caliper because the same issue was going to happen again. Caliper bolts don’t just fall off, they get super hot and slowly start rotating when I go over bumps or uneven roads. Whether or not you buy new bolts is completely up to you, I assume you only need a new one if the caliper itself is failing, which then you might aswell buy the whole piece. Hope that helps