Yeah, Filoni seems to not consider the scene canon either, considering he acts clueless as to what happens in the palace, stating the fight was "probably" four times as long, and instead seems to leave it to our imagination.
Furthermore, Maul being capable of outright overpowering Sidious in a force grip is contradicting to what we see in the beginning: Sidious overpowering both Maul and Savage at the same time, with them being unable to break his hold on them despite Sidious putting no effort in it whatsoever (and when Sidious casually force pulling them off the balcony as he was falling, with them being unable to do anything about it). But then suddenly Maul manages to overpower Sidious by himself, with Sidious being unable to break Maul's grip? Hell, Yoda wasn't even capable of holding Sidious down or directly grip Sidious with the force, which according to Sidious in The Book of the Sith, Requires more power and concentration than a force push. Also, when Maul was bathed in pure rage after watching his brother die, while Sidious stands back and laughs at Maul's suffering and then proceeds to taunt him about being replace, was absolutely defenseless against Sidious force powers after being disarmed.
So I'm not sure how canon the scene is, but I'm hesitant on accepting it because of it's contradictions, and the fact that Filoni doesn't really seem to acknowledge the details in the scene as absolute canon; he wouldn't make comments about Sidious' absolute dominance over them. As for the argument about Savage knocking Sidious over the balcony, that's because Sidious gave Savage that advantage by toying around, it wasn't because they were pressing Sidious, thus Savage knocking him over isn't really Sidious wavering from his position of superiority. However, Sidious being outright defenseless against Maul's grip, only being saved by a hanging light, is wavering away from his position of superiority. For instance, I use to play fight with my younger sister when we were growing up, and she would knock me off of balance a few times because I wasn't fighting her my hardest and I was just toying around with her, but that wasn't exactly me wavering from my position of superiority, it was me giving her moments to take advantage of by not taking her seriously. Now, if she had managed to pin me down, and I was unable to break free from her strength, then that would be me wavering from my position of superiority.