Deal Analysis (Just learning) - What am I misunderstanding?

[Robert Horvick]

I found a property on Zillow and ran the asking price numbers through the BP calculators and came up with $439/month cash flow at 39% ROI. Both BP and Zillow agree on the rent estimate and it doesn't seem out of line for the area (maybe 15% higher than I expected but still in the ballpark) I've only been researching properties for a couple of days (and still not made a first deal) - and this feels like it's too good. I have linked the report here:

https://www.biggerpockets.com/...

My question is if you were looking at this report and wanted to validate that the numbers were sensible - how would you proceed?

Thanks!