Well considering that the inside of someone’s home isn’t a public space, that would be quite true. However, intent would also come into account.
“However, if a camera points somewhere private (e.g., into someone's bedroom window) then there may be a privacy concern. While the camera is situated outside, it cannot generally be oriented in a manner intended to invade an area where someone has a reasonable expectation of privacy.”
https://www.hg.org/article.asp?id=35154
Obviously I can’t setup a camera that specifically and intentionally tries to record the inside of your home. However, if someone’s doorbell or floodlight camera happens to coincidentally have their across-the-street neighbor’s living room in part of the frame, which is practically a guarantee for a large number of such cameras, then that would seem to be perfectly fine.
I’d also like to see the details of the case you’re referencing, because at face value, it doesn’t seem to have much to do with the discussion here.
The reference you used stated the following:
"While the camera is situated outside, it cannot generally be oriented in a manner intended to invade an area where someone has a reasonable expectation of privacy. That is especially true if the camera has enhanced capabilities that allow it to see through obstructions or in the dark."
Note that it stated "in the dark". Given that the camera has night vision, I am not sure if it is acceptable.
Note: a human eye has an ISO of 800. (https://wolfcrow.com/blog/notes-by-dr-optoglass-sensitivity-and-iso-of-the-human-eye/)
Although I do not know how high is the ISO for the doorbell's camera (they do not list it), it is clear that it would be way more than what the human eyes are capable of based on looking at the pictures alone.
Additionally, it stated again and again the importance of "reasonable expectation of privacy". That definition is not very well defined and is going to be based upon each individual, where I would expect privacy at my own porch and not getting recorded by someone in the neighborhood without my permission because it is technically not "in the street".
Hence I said that is a very slippery slope for privacy.
On the other hand, the case I was referencing - The man naked inside his own home was aquitted of indecent exposure.
http://www.foxnews.com/us/2010/04/07/va-man-acquitted-flashing-passers-home.html