I know what I think are the key indicators, and I think I have reliable sources of information, but I'd love if you could share some of what you look for when identifying growth markets. 

Zillow and other sites can give you a graph and a Heat Map indicator of Sales in each area.

The benefit to me:-Potential cashflow w/ minimal investment-Ability to potentially negotiate lower selling priceBenefit to Seller:-Ability to find appropriate 1031 property and not be rushed by 1031 timeline requirements-Peace of mind that mortgage will be paid and he can sell wheneverQuestions:How would I calculate the correct lease price?

Some contracts indicate a Per diem for delayed closing..

So, although I see what your measurements are trying to do, I think you'd need to run the same numbers on some other markets like DFW, Cali, Florida, Atlanta, Chicago, etc to see if its really accurate indication or if its just coincidence. 

However, as indicated above they said one day is the same as 30 days late.  

@Jeff Gore, nothing in this post indicates a history of ongoing anything....This appears to be a single event with no significant issues resulting from it.

This is not to indicate it is impossible.  

If I were you, I would record a voice mail greeting indicating that "if you are calling about property x, I am no longer interested in selling it / I already have an agent, etc."  

They can give you pretty good estimates on the numbers which could indicate whether or not you should dig deeper into the research of a particular property.