Technically if the MACOs hadn't gone trigger happy none of it would have happened..
Which is ALSO not a Federation value, and not an expression of the Federation's value of exploration as important.
Though the idea that those MACOs bear responsibility for Sedin's actions is quite silly.
They're responsible for their decision to attack the Caeliar, nothing more. The Time-Dispalced-Caeliar are responsible for
their decision to maintain the predestination paradox that created them and displaced the one Caeliar city-ship with the MACOs aboard into the Delta Quadrant of the distant past. And Sedin is responsible for her decision to murder her fellow surviving Caeliar and enslave the surviving Humans.
And to go further: The Caeliar gestalt is responsible for
its decision to imprison the
Columbia crew. Captain Hernandez is responsible for
her decision to travel to Erigol. And the Romulans are responsible for
their decision to start the Earth-Romulus War and attack the
Columbia. But not a one of them are responsible for the creation of the Borg other than Sedin.