2 shaman mains and a chanter bot, healer/tank/rogue mercs. shaman pulled, hit with a 55k nuke on way back to group. Here's what I see in my logs for the duration of this fight as far as his spell casting is concerned.
$ cat /cygdrive/c/Users/Public/Sony\ Online\ Entertainment/Installed\ Games/EverQuest/Logs/eqlog_Azgoth_drinal.txt | grep -i "sheartooth captain begins to cast" [Sun Apr 06 10:39:31 2014] Sheartooth Captain begins to cast a spell. <Telazekaria> [Sun Apr 06 10:39:46 2014] Sheartooth Captain begins to cast a spell. <Telazekaria> [Sun Apr 06 10:39:50 2014] Sheartooth Captain begins to cast a spell. <Mental Breakdown> [Sun Apr 06 10:39:58 2014] Sheartooth Captain begins to cast a spell. <Concussive Respite> [Sun Apr 06 10:40:02 2014] Sheartooth Captain begins to cast a spell. <Telazekaria> [Sun Apr 06 10:40:22 2014] Sheartooth Captain begins to cast a spell. <Telazekaria> [Sun Apr 06 10:40:30 2014] Sheartooth Captain begins to cast a spell. <Concussive Respite> [Sun Apr 06 10:40:34 2014] Sheartooth Captain begins to cast a spell. <Telazekaria> [Sun Apr 06 10:40:54 2014] Sheartooth Captain begins to cast a spell. <Concussive Respite> [Sun Apr 06 10:40:58 2014] Sheartooth Captain begins to cast a spell. <Circle of Lightning> [Sun Apr 06 10:41:04 2014] Sheartooth Captain begins to cast a spell. <Telazekaria> [Sun Apr 06 10:41:16 2014] Sheartooth Captain begins to cast a spell. <Telazekaria> [Sun Apr 06 10:41:24 2014] Sheartooth Captain begins to cast a spell. <Concussive Respite> [Sun Apr 06 10:41:28 2014] Sheartooth Captain begins to cast a spell. <Telazekaria> [Sun Apr 06 10:41:56 2014] Sheartooth Captain begins to cast a spell. <Telazekaria> [Sun Apr 06 10:42:00 2014] Sheartooth Captain begins to cast a spell. <Mental Breakdown> [Sun Apr 06 10:42:16 2014] Sheartooth Captain begins to cast a spell. <Telazekaria> [Sun Apr 06 10:42:32 2014] Sheartooth Captain begins to cast a spell. <Telazekaria> [Sun Apr 06 10:42:36 2014] Sheartooth Captain begins to cast a spell. <Concussive Respite> [Sun Apr 06 10:42:48 2014] Sheartooth Captain begins to cast a spell. <Telazekaria> [Sun Apr 06 10:43:04 2014] Sheartooth Captain begins to cast a spell. <Telazekaria> [Sun Apr 06 10:43:16 2014] Sheartooth Captain begins to cast a spell. <Telazekaria>