I know its not what your asking, but all that grime around the leaks is suspicious.  

It just seems suspicious that he won’t allow inspections since he says everything meets code and works. 

She called me because the picture window in her living room spontaneously exploded and the owner (also the failed flipper) blamed her, well come to find out this genius cut a big hole in a load bearing exterior wall for this window but had neglected to put a header in so when a big heavy snow came, the pressure was too much for the window and it followed the path of least resistance. this happened 2 consecutive winters. a home inspector would not have caught that because it is hidden behind sheetrock but if the work had been permitted, it never would fly. my point is that an inspector can only inspect what they can see and that many flippers either have no clue what they are doing, are trying to cut corners, or don't care. there ARE some good and responsible flippers but when I know a house has been flipped, I am always suspicious.

So it does happen, but multiple and highest and best would seem suspicious...but I can believe it happens.

I would be suspicious, especially given that it is on Craigslist. 

I was also suspicious.

Thought it sounded suspicious so talked to the neighbors.

At first the cops were pretty suspicious, but then MLGW showed up to save me corroborate my story.Funnily enough, the poor neighbor got yelled at by MPD.

I'm suspicious of anyone who can guarantee anything.  

I would also be very suspicious of someone selling a property that they bought less than 6 months ago.