What does being the first character shown in Replay mean?

In replays, raid members are usually shown up one by one. For some members, they will show up when they use their first cast. However in this log replay Warcraft Logs - Combat Analysis for Warcraft, a Shaman (Mobcycle) shows up as the first character, but I cannot find any cast log from him at that time. What does it mean as being the first one shown in replay in this case then?