except according to you he wasn't teaching Daito-ryu by that point and had "changed", well before actually. So how would he be angry at people for doing something he wasn't teaching, wasn't talking about and something that wasn't really discussed within his organization at that time?
Quite simple really. See it all the time. People reverting to what they used to do or even thinking, as many still do now, that he must be doing those secret internal daito ryu stuff.
Still in the old time samurai mindset.