I too have been battling for a while myself and I assure you if you do a little more research you will find out that what you experienced was not uncommon by any means and as the ability states it hits 100% of the time under any circumstance, the only moves that I know of that can stop an attack from a No Guard Machamp are Protect and Detect. If you want to test it out get a friend to battle you on a simulator and then use a No Guard Machamp against a Gyarados using Bounce like in our battle and you will see the exact same thing will happen. And trust me I take no offense to your questions, I just figured I would clear it up for you so you know for the future.