^That's true, Earth shouldn't have gone around blabbing about Vulcan's secret spy base, even if they were technically in the wrong...
"...technically in the wrong"...?

There was a Vulcan/Andorian treaty, wasn't there? There was a big-ass listening station on P'Jem, wasn't there? Protected by "humanoid shields" who, as
bluedana pointed out, blithely said nothing while their guests were being beaten up by their Andorian kidnappers?
Treaties are promises. They are expressions of mutual trust. When a treaty is signed by two races as a means of keeping them from trying to annihilate each other, it provides protection to
both sides. One side cannot cavalierly dismiss the promise made, for whatever reason, without expecting (not to mention
earning) potentially dire consequences if the violation is discovered. No matter who discovers it.
So the Andorians are suspicious bullies. Fine. But they have
honor-- more than the Vulcans. The Andorians stuck to the treaty, and the Vulcans violated it.
T'Pol consistently demonstrated far more honor than most other Vulcans on
Enterprise. The writers' choice to have her hand over her tricorder to Shran, rather than for a non-Vulcan to do it, illustrated the irony of the situation, as well as showing us T'Pol's sense of honor. As for Archer, he was trying to learn to trust the Vulcans, but they certainly didn't make it easy for him, considering their penchant for deception throughout the series. He came to trust T'Pol because she demonstrated her trustworthiness.