What if he did? That's a red herring.
The issue has not been what language Jesus spoke, but what language the Gospels were originally written in. Is it impossible for one of the Gospel authors to have translated what Jesus said into Greek, without needing to write it down in Hebrew first?
There is no "What if he did?", there is NO doubt Yeshua taught in Hebrew as he would have been tossed out otherwise.
The issue has not been what language Jesus spoke, but what language the Gospels were originally written in. Is it impossible for one of the Gospel authors to have translated what Jesus said into Greek, without needing to write it down in Hebrew first?
Common sense dictates it was first written in Hebrew, since it was taught and no doubt used as reference, and since the Hebrew people despised anything Greek, it would not have been allowed and would have discredited anyone who attempted to do so.
Also, see the previous testimony we have that I've listed upstream.