i think is pretty clear from the background when the mc talk to sage (just look at the walls from the library room in diks house, the room that has a beer barrel and a lot of books and things in the floor), that sage is the one that did the whole thing of cathys, quinn may knows the diks password for many reasons, tommy being one, she has every reason to make rusty take the fall, thats means tommy will be president and that will make it easier to make the diks her dealers with the whole drugs thing,
also im pretty sure dawe did convinced quinn somehows, quinn is pretty Smart and the truth is that she may do this for other reasons while also take advantage of dawe for making trouble for the diks.
All in all is a win for her and the hots... Riona being concerned and kissing a diks mcs... is even more making me believe this.