The timer for Rokmora's Razor Shards seems to be off. The timer for the first cast is fine but everyone after that is off by about 5 seconds.

https://www.warcraftlogs.com/reports/F7p4xtG1HkWbcmLM#fight=last&phase=1&type=casts&hostility=1&start=49840338&end=49992279&source=358