I'm almost certain this was a case of instructor teaches in BM only(infact, I'm 98% this is the same instructor I went through for all my Cavern/Cave courses), for the reasoning that they(instructor) dive BM primarily.
IMO, thats a good call on the instructor's part. If they don't have the experience in SM, I'd rather they not try to teach me in that configuration. Part of knowing their own limits.
If at that point, you want instruction while in SM, you just go to a SM capable instructor.
FWIW, I know that my instructor has been doing alot of SM diving this year, so he might be teaching in that configuration in the future - but not until he's sure he's competant in it. No need to be like the rash of other new SM instructors, who've JUST learned to dive that way and want to teach it.
[ignorance]
If someone takes SideMount from an instructor, and . . . gets certified? I don't know, can you get certified in Sidemount? . . . Can that same person then go take Tec or Cave from an instructor that dives BackMount?
It seems if they are already trained and comfortable in their configuration, then it should not impact on the class . . .
[/ignorance]