Have we Already come to this point?

I watched as my son rode away this weekend..well not far...rode away to the neighbor's house a block down the street. Considering there was a time, not so long ago, that Austin going in the front without someone watching was a big no no..so this was a huge step. The home is visible from our front door so there are no problems seeing where he is going. We have been familiar with the family ever since their dog wandered up to our home one rainy night two years ago, only a puppy then, and spent the evening in our den getting dried off and fed until she was full....so we aren't worried about the people in the house. Worry comes because this is his next step into independence. It's necessary. It's Imminent. He's a nine year old boy, mom....let's get with the program.
The neighbor came to the door, knocked and asked the question most parents hear after some time living among the same people that have children..."Can Austin come over and play?"...Uhhhhhh....
Have we already come to this point where he can just go off by himself? What do I say? Do I bring him in my car? No. Not for four houses Farrah, come on.
Will he ride his bike alone? What?
Yes? No? Yes? No? Ok. yes....Not a moment had passed between the time that I spoke that word and him jumping on his scooter and he was off down the street. I quickly shouted "One Hour!!" and barely got a "K!" before he was out of earshot.
Next Question:Do I watch him?
What is the protocol for staying cool and keeping him safe all at the same time? Watch? Close the door and hope for the best? Watch? Close the door and peer out the window? Peer.... But what if I'm spotted and Austin is branded the kid in the neighborhood with the weird mom that watches you from the window? We can't have that.
Best alternative...grab the binoculars and peer inconspicuously from a distance out the window....far more normal...I mean, I could be bird watching for all they know. There just comes a time where you have to trust that everything you've taught him, he will remember.
An hour later, Austin came back in alone, pink cheeked, and happy. They had a good time and he was back on time. One hour and he stuck to it....Good kid.