Tying a red thread or cord around the wrist is a Hindu practice and it is unlikely a Muslim, especially one politicized enough to carry out an attack such as this, would observe it. I think this provides more evidence that this was a false flag operation or at least an attack by a non-Muslim group. For more information about the significance of the red thread see wikipedia.
Additionally, the terrorists inside the Nariman House Building were reported to have stocked up on supplies on Wednesday evening, buying not just food items but liquor, among other things, from a local store. Again, it is highly unlikely that a Muslim, let alone a ‘Mujahid’, and especially one politicized enough to carry out such an attack, would consume liquor in normal life, let alone hours before his inevitable ‘martyrdom’.