It's pretty accurate. I did not read it with outmost care (I used speed-reading) but it looked OK to me except for a couple of things:
1) stress bars are not always what they picture there, black lines are also stress bars.
2) black feathers can be caused both by malnutrition AND stress.
3) the red feathers in the gray are attributed only to PBFD but they can also be plucked feathers that grew back red.
4) the feather discoloration (where they show the red-suffused lovebird) is attributed to a generic malnutrition when, in reality, it's a direct consequence of liver disease so the 'cure' (a pelleted diet) would not have cured it.
5) the only canaries that get feather cysts from 'soft' plumage are the ones that were not bred correctly (you can't breed a hard feather to a hard feather or a soft feather to a soft feather, you can only breed soft to hard)
6) Polyoma is not the only cause of French molt, pox does it, too.