The Dynatrons were new and the original HS compound was used. All screws were tightened down snug so I don't see where it could have been an error.
I don't know what to tell you, maybe the compound that comes on them is not good? (I don't use it).
Maybe yours was slightly bent in shippng and wasn't installed firmly enough? I've had some HSF that even when tightened the whole way barely touched the CPU so that when removed the thermal compound was barely touching/on the CPU, and would cause the CPU to consistently raise temps until throttle.
I do know I have over a dozen of them and I know for a fact that they cool better than the SuperMicro Active 2U HSF because I've replaced a handful of them with R14 for the better/quieter cooling. And, as I said if you replaced the 2U HSF with a 4U HSF then that is understandable you'd get better cooling at idle but at full-usage they both will keep the CPU cool/usable too.
I'm not sure what motherboard you're using either but I had R14s that let my 2011 E5-2670 get up to 80*C+ at load and by changing the fan profile completely changed it, and dropped them down into the 60s at load. Of course this was higher fan speed, and louder but the R14 have absolutely 0 problem keeping the CPUs cool.
Since you've not told us what your thermal paste looked like upon removal, if you went to a 4U hsf, etc.. I'm just sharing info that I know to be true based on my experience with numerous installs.