I've ignored Sage long ago.
Just do the same.
You are unlikely to get any form of intelligent two sided debate from him/her.
In my experience he/she will spout unproven/fictional nonsense then when/if someone calls him/her on it, he/she will resort to personal attacks.
Advise that remains valid.
You guys would be better off if you just ignore sage.
Sage seems to just like instigating conflicts.