I think it's safe to say that Dean knows Sam a lot better than Sam knows Dean at this stage. Also, he's had their father's example in front of him his entire life, has seen first hand how destructive vengeful grief can be, and as much as he idolises his dad, I think he'd hate to see Sam end up the same way. He's a mass of contradictions, is Dean, because throughout season one he wouldn't dream of saying a word against John. I don't think he even allows himself to consciously think any criticism of John. But he also tries hard to avoid making the same mistakes and to prevent Sam from following the same path, which speaks volumes.

Absolutely! It's one of the main themes of S1 that Sam really only gets to know Dean as a person on their roadtrip. I very much agree with Dean avoiding to make the same mistakes as John. I always found the fact that Dean handles kids in distress so much differently than John does, that it shows how much he subconsciously suffers from his father's inability to communicate his care and love for his sons. Also, the way he handles Sam (in flashbacks as well as in the present) shows that he did so from a very early age on. It's kind of a silent criticism towards John, that I am not sure he's even aware of. :)

See how you found so much to love about Wendigo LOL

I always knew that! ;) The brother's dynamics always provide a strong pull for me, no matter the episode. For some reason I am just more annoyed by the MotW in this one than in some others. LOL