I don’t think this is a bug. The Analyze is outputting the pixel that has the lowest luminance. That is the pixel with (-1, -1, -1). No other pixel creates a lower luminance, since G is 60% of luminance. If you use a reorder to switch R and G channels, then you’ll see a different pixel win.
What you expected to see was what I expected to see - the lowest value of red in the image, the lowest value of green, etc just like the default Analyze CHOP does, which treats each channel separately and gives you the minimum for each channel.
The default Analyze TOP takes the luminance of each pixel (a blend of R, G and B) and picks the pixel with the lowest luminance, and outputs the pixel with the lowest luminance. This may not be the pixel with the lowest value in red, for example.
Even the option to use Red instead of Luminance gives you the pixel with the lowest red, but that will not necessarily be the pixel with the lowest green.
We will add the options to give what you expect, but until then, you will have to do 3 Analyze TOPs to get the lowest red, green and blue separately. I’ll add a note to the wiki.