Understating expenses, and overstating rent roll and occupancy, by lots.

Realizing that most people will overstate what they offer rather than understate it, whereas I do the opposite.The first of these, I think, was imbued in me as part of my Roman Catholic upbringing.

If you know what you are getting in to and understant the risks and rewards, you can invest anywhere. 

We allowed the place to do needed repairs-water line running under state route 31 was a big project.

That is illegal and may actually be criminal under state and federal law.

To summarize, if you are approached by a syndicator raising money for a multi-family building that meets this multiple offer fact pattern (as is usually the case) who is awarded the contact, they more than likely assumed the most ambitious rent growth, most understated cap ex costs or operating expenses or lastly the cost of equity (your return) is projected to be less than the LP’s the other bidders relied upon.

That being said the only way these low cost providers could protect themselves would be to write their programs in such a way that the benefit their work provides is so low compared to the reality of what is allowable that there isn't any chance of overstatement of depreciation, which means it would be understated and you're leaving money on the table. 

@Sneha DeshmukhI think repairs and Capex are way understated. 

Grossly understating the amount of KNOWLEDGE and experience necessary to protect your capital from loss2.

Most of the time they will understate the repairs needed so factor that in.