This is very common with the rb motors. You can buy a collared bolt that prevents this from happening. I had it on my rb.
196nm is 144 ft lbs,that's too tight. It's 43-56 nm if I'm reading the manual correctly. It's a bit blurry on the inter web. 196nn is tighter than a banjo string. I've always done it by feel. I bet that belt was singing.