I received a notice this morning that Amazon's data center had some issues last night and it appears that this caused corruption with the playback data. If you click the "next play" button it seems to be able to continue, skipping the corrupt play, but I don't know how many plays or games were affected. It does seem to only have impacted the games that were simmed last night. The game results and stats were not impacted, just the playback keyframes.
"Between 12:08 AM and 3:40 AM PDT, Amazon S3 experienced elevated error rates and latencies. We identified the root cause and pursued multiple paths to recovery. The error has been corrected and the service is operating normally."
This of course smack dab in the middle of the game engine running for most leagues. **sigh**