My drone went into RTH after losing contact,

It didn't go to RTH altitude, It just came back in the same sports mode without any obstacle avoidances.

It's very litely that I would have never get contact back with the drone going behind that building and heading face first into it.

Also if ever my google battery would have disconnected it'd would have taken about 2min for the google to boot back up, and I could not have avoided that building.

Hello there. I am sorry to know what happened to your DJI FPV and thank you for reaching out. Since this unfortunate event happened to your DJI FPV, I would recommend for you to contact our DJI Support Team at https://www.dji.com/support?site=brandsite&from=nav for further assistance with regards to this matter. We will do there best to help you and give out the best resolution for the said issue. Again, I am sorry and thank you.

I was under the impression that it needs to be in N mode in order for obstacle avoidance to be engaged. This may also be true for RTH mode, so when it goes into RTH, switch it into N? Sorry, I'm a Newbie, too....

Maybe someone's could confirm that auto RTH use the same mode as it was in before.

I think that's a problem, and since the RTH speed is the same as N why not enable obstacle avoidance when retuning?