That's a signficant difference from shortdata.ca 

Stockwatch's number is current up to May 31st, stockwatch.ca has a date of June 1st for their number which is 2,047,538...

Either way it shows that up to the end of May or the start of June....shorts weren't covering off, their positions were increasing. 

Why?

I think it is entirely possible that those who are short, that they are between a rock and a hard place.  Buying back causes the PPS to move higher, and a climbing share price does not engender feelings of Fear Uncertainty and Doubt (FUD), quite the opposite in fact.  Its possible too that Don has attracted some buyers with recent presentations....which could mean more competition for those caught short and looking to cover.  And shareholders are not going to be discouraged by a share price that is climbing in spite of precious little news. 

So in this context, increasing the level of short selling has some logic.....keeping a lid on the PPS in hopes of discouraging anyone possibly looking to dip a toe while hopefully wearing out the patience of some long suffering shareholders.