Gasil newsletter:
http://www.caa.co.uk/docs/33/srg_gad_gasil4of2003.pdf
In Particular Pages 22 and 30. I wish I could find my notes from Uni for some quotes, but again the things I was taught about Human Behaviour and interfacing with machinery, and designing to "mistake proof" seems to be in very sharp contrast to what we see in those pictures.
I do hear what you are saying though about the PA28, its 25+ years old so the technology is that of 25+ years ago and a similar situation would probably not occur on a newer Aircraft?