A sample rant
It always bugs me when people talk about canon as though it's gospel. The creators of a show are fallible human beings. They don't always get it right.
Look at The X-Files. Fan writers kept far better track of the mythology behind the series than the actual pro writers did. There are several examples of continuity slips in the television show, from small (the number of brothers Scully had changed) to large (the origin of the X-Files themselves was given in a first season episode, then contradicted completely in a fifth season show.)
It also pisses me off when people say that the creator could never write one of their own characters out of character. Sure they can, if their writing is sloppy.
If you make up a character named Indiana Jones and establish that he's afraid of snakes, you have to stick to that. Later, when he's dropped into a pit of snakes, Indy should be scared. If he's not, and you don't explain his lack of fear, then you're writing him out of character-- even if you made him up in the first place.
I'm all for being aware of canon and characterization, but I'm not into slavish, blind devotion in any form. Sometimes even the pros don't get it right, and it's okay to acknowledge the fuckups and missteps; few things on this earth are perfect, no matter how much you love them.