Very simple:
1) Give you current watch to your spouse
2) Buy same watch from Apple
3) When it arrives, it'll have WatchOS 1 on it.
Seriously, can we sticky something at the top to tell people you can't go back. Or how about on the download page in nice big red letters.
Even better if Apple would notice the issue and provide a way to downgrade. There must be a way to do it. Chances are watches will get bricked with bad firmware updates. They need a way to fix it. No one writes software without bugs.
Historically speaking, its never been super easy to downgrade to an older version unless it's an OS...and even then just hope there wasn't a bios update involved.
I think there is good and bad to being early adopters. For me I just have to be a little careful since I don't have a spare watch or iphones to work on. I think the update to Watch OS 2 was probably the guttest thing I've done.
Live and learn. I will clearly heed the warning. I will not be able to afford trying beta versions of the OS in the future. I don't have unused duplicate set of devices laying around. I'm completely stuck either without a watch or without an iPhone for development. Very unfortunate.