Sprinting? Clearly an over-watt condition; just too many watts for the cleat to handle. Either get off the juice, or get DTC (droping teh hamer) certified cleats, which are basically kryptonite reinforced diamond nanofiber (with a cosmetic 3k carbon weave).

In all seriousness, you can see the washer indents, and it looks like they were too small diameter and overtorqued, which as mentioned above, was almost certainly the cause of the failure.