wabalaba (US shorts tracking) doesn't show any recent KXLAF shorting activity. KXL only shows up in the "dropped" category, 4 times in the last 2 years.
Sprott sold during last December/January's top when KXL was over $4, and the shorts usually sell on a peak in share prices. No peak now.
By the way, it's not a good idea to use Sprott's holdings as a guide, unless you drive your car by looking in the rear view mirror with binoculars:
Globe and Mail on Sprott.
When Sprott buys and sells, you find out about it long afterwards. Sprott could have taken another big position in KXL now and you wouldn't know until November.