That was one mean puffer Fish to eat that Clown,I have a Huma Trigger with a Blue Line Grouper.I have several Tanks with Trigger and Grouper mixes.In my Experiences Humas generally get along with Niger Triggers and most Groupers and Snowflake Eels.I have rarely seen a problem with Huma Triggers with Groupers or Niger Triggers.Keep in mind that some Humas can be agressive sometimes.
Good luck