But, there are plenty of horror stories where investors buy properties and they fail fairly quickly and then no one is there to help them.  

You also failed to mention that the new contract price was exactly the same as the one you previously signed. 

If the tenant fails to provide proof, I would reach out to a local attorney about handling the lease violation appropriately, especially since Texas has specific landlord-tenant laws.

The #1 reason that landlords fail is due to failure to manage to the lease (Source: American Apartment Owners' Assn). 

If the $700K sales price is not used correctly to acquire qualified real estate, the exchange could fail, triggering tax liability.Future exchanges will depend on the total value of the replacement property acquired, so entering syndications could limit flexibility.

Everything was smooth until it wasn’t. 6 months into it the tenant called and the toilet had failed in an upstairs bathroom.

That pace feels pretty good to me...I can get past the "rookie mistake" phase of my career before there is investor money on the line, and I can "fail small" because SFRs and small multifamily doesn't hurt as much as larger properties when things go wrong.Timing had a role, too.

People who are successful versus failed with OOS tend to follow certain patterns.

But with perseverance and a willingness to explore unconventional options, you can turn even the toughest situations into successes.Have any of you ever faced a deal that seemed destined to fail?

There have been brokerages offering flat fees and failed.