You interpret it to be referring to the following sentence. In a court, a lawyer could extremely easily say this was not referring to the accusation in the previous sentence. It stands alone.

Each statement can be proved to be correct individually. They do not have to refer to each other from a legal standpoint.

"are consistent with the methods and motivations of Russian-directed efforts"

The methods can be anything referring to hacking. Anyone who hacked the DNC would have been using methods (hacking) consistent with previous Russian hacking attempts.

Motivations? Motivations can be defined as someone wanting to take private information and making it public.

Read it like a lawyer. There is a reason why these statements are carefully crafter.