You are correct. There is wisdom in the saying, "perception is everything." For the reasons you state and more, even if no terrorism was involved in this crash, our militant Muslim enemies will read a divine message into it. They will view this as a message of encouragement from Allah to continue the struggle.
Just as we have are on the verge of breaking the spirit and morale of the pro-Taliban forces completely, this happens. It might serve to be short-lived morale boost, but it will result in a morale boost nonetheless.
A terrible and unfortunate incident all the way round.