Here’s the culprit!

I would like to add 1 correction to this post... Iroh was not leading his brothers troops in the siege of Ba Sing Se, these were still his father Azulon’s troops. Iroh was on his way home when Ozia had Zuko’s mom kill Azulon to protect Zuko and therefore allowing Ozia to usurp the throne from Iroh (as Iroh was next…