Exactly the same thing happened to FostersMonster 2 years ago, we were on our Lakeland trip and on the way back he totally lost the bolts holing the front caliper. He tightened the caliper to his fork leg with some zip ties and made the journey back on his back brake only. Scary **** as we had to drive on the motorway. Locktite is good but it's no substitute for regualr check up on all your bolts and something you can easily do yourself on a weekly basis.
Hold on to your nuts by keeping them well tight is what I say