Aly entered BB (or BB planted Aly) to go against rubinav (and BB actually need this... 2 strong opponents) and to up the game of jasmine(as just usse phle wkw me she was the puppet), it was very clear on the very first day when he said k jasmin pavitra n naina ko bahar se jaanta hu aur kisi se lena dena nhi
But the thing is in the captaincy task he promised Rahul to help him to become next captain not to save from nomination...and he promised Abhinav that he will save Rubina from nomination .....
So this task was actually given by BB to open eyes for Rubina ( may be this lead to elimination of Abhinav) to play her game actively unlike what she did in captaincy task.....and this task was also given by BB to show who are on priority list of Aly coz iss phle to he was also playing ghar ghar.... Chillao phr sorry bolo(nikki case, devil task) ...
It was actually to check Aly's mind whether he'll go against abhinav (Rubina) or Rahul.....
I think he did betray but it is right for the game depend on what impact it has on Rubina
I also feel this time is good to send abhinav to secret room or may be abhinav and eijaz (so they bond well there and form another team with Rubina)