You said it yourself and still dont believe about who could be behind the attack. Just see who is gaining in popularity and you will know who is behind the attack. PMLN cant be that stupid to calculate the risk of this attack. This could be self planned one. I dont see any reason why the killers ran away after killing only the ‘friends’ of Shaikh Rasheed, and he got hit only in the foot.
If PMLN is behind it, then they either need to hire better assassins or get some tips from MQM on how to eliminate opposition properly.