Trying to understand: Thestalos vs. Sangan

[Dr Sin]

I saw this on the organized play forums
link: http://entertainment.upperdeck.com/op/community/forums/thread/748971.aspx

The scenario:
TP activates his Soul Exchange targeting opponent's Sangan. NTP has no cards in hand.
TP tributes for Thestalos.

Answer from Curtis:

When you Tribute a monster with a mandatory Trigger Effect that activates as a result of the monster being Tributed, the Tributed monster's effect is placed first on the Chain.

Refering to this situation, "Sangan" is placed first onto the Chain because its Trigger Effect activated when it was Tributed, followed by "Thestalos the Firestorm Monarch".

"Thestalos the Firestorm Monarch's" effect will resolve first, followed by "Sangan".

I understood Curtis explanation, but something sounds strange to me (bolded part): the effect of Sangan doesn't activate as a result of him being tributed, but because he goes to the grave.
I can be overthinking about it (usually I do that) but doesn't this kind of situation leads to dangerous interpretations? It sounds like the tribute summon had a spell speed, since the appearence of Thestalos on the field and Sangan reaching the grave are not being treated as simultaneos events, thus forming a SEGOC. And this is confusing me a bit...
Sorry if it sounds strange, but I hope someone understood my doubt and help me understand this.

Thanks in advance.

 

[densetsu_x]

You have to "micromanage" this a little bit for it to make more sense.

You tribute Sangan with Thestalos. Sangan is in the Graveyard at this point however noone said that the summon was successful. You could still interrupt it with Forced Back or Solemn Judgment and the like. Sangan's effect though would already be waiting to activate on the chain regardless what happens to Thestalos. So it's not quite a SEGOC since Sangan is a half-step ahead. Now if the summon isn't negated, then Thestalos' effect will activate too as Chain Link 2 (and thereby resolve first).