Begging the Question in Middle-Eastern Geopolitics

On the TV today they were on about how the Syrian army has finally completely left Lebanon. What I've found fascinating about this story is how everyone points to the Hariri assassination as the trigger for the Syrian pullback. The official narrative went something like this though:

Hariri has been assassinated! How soon before Syria ends this meddling?

Ummmmm, pardonez moi? I am fascinated how they've never actually shown that Syria did this. They haven't shown that the bomb was of a type that Syrian agents prefer, they haven't caught any Syrian agents in connection with this crime. Look at the effects of this event: Syria is isolated and weakened in the region, Lebanon is ardently opposed to Syria and even looking at the US as vaguely benevolent. Who does this benefit? I think it's pretty obvious. And I don't think that's it's a tinfoil-hat conspiracy to suggest that it's very possible that Hariri's assassins were operating under the aegis of the US government.

Now it's probably just as likely that Syria's leaders are inept and somehow thought that this assassination would somehow benefit them. But the utter lack of evidence linking Syria to the bomb makes me wonder.