Leaf spring hitting shock?

Well I was takeing my tire off today to repaint my rear drums black and I noticed my shock body is dented/creased in two places. From what it looks like two of my leaf spring shifted at some point and hit the shock. All the u-bolts are torqued to spec so what could cause this and has anybody else experienced this? I have a Toytec 2" rear AAL and Rough Country 8000 series hydraulic shocks.

 

Flex your truck slowly with someone watching to see if it's possible to make the leaf spring touch the shock.

 

When I put the tire back on and lowered the truck back down it didnt look like it even came close to touching? And the suspension was at full droop. But maybe it happends when the suspension flexes IN on that side..

 

Looks like whatever hit it did it once and it hasn't happened for a while since there's rust in the dent. I'd try flexing it out and seeing if you can replicate it. Keep in mind if you come off something tall you'll compress the suspension a lot more than just flexing the truck slow and controlled.