The old Warren Buffett saying comes to mind: if you can't identify the pasty at the poker table, then it is you....
We have all been there to some extent. I have been for sure...
There is asymetry in information in some transactions (they know more than us, or share less info). Interests diverge... We just don't have enough info or are at some disadvantage (like being far away).
It sounds like you may have gotten the short end of the stick being the the absentee buyer from silicon valley (next time--tell them you are in waste management with vague references to possible Soprano style ties... leave the FB word out of it).
They are looking to match a duplex with some issues with the right buyer and one from out of state (from highest housing market in the country) shows up......may not even get a good look...hmmm (so what are the rules to this poker thing again? and how much can I bet?)....
There seem too many things wrong with the place or on the edge of going out. They should have shown up from an inspection, buyer's agent, etc.
But you can surmount them all with some good professional management on the ground.
Of course, you also play a role being on the outside looking in from afar. Perhaps you could find a better deal a couple of hours East in the Central Valley and get to build some relationships with people in the industry (but Austin is probably hipper than Stockton). You could drive over, too, in CA.
What is next? I like how Dave Ramsey just calls it a tax (on making a dumb move) or tuition.
Your Austin deal was an entire seminar on how not to buy a multi-unit property.
And some of those "educational" products for real estate run 50K+ and you don't even get a property out of it.
So bright side, as everyone mentions, you learned alot, got your first place, and have a better idea of how to proceed (or slow down).
Best of luck!