The fact is, pbmining paid out weekly with no downtime since they started. And they were honest since, and maybe they are telling the truth still.
Since the location of the mining rigs maybe compromised. It is possible that they are using lesser mining rigs for now, until they move to a more secure location. That might be the reason for the substantial loss of hashing.
LOCATION COMPROMISED? - THERE IS NOT AN ELITE SQUAD OF HITMANN THAT ROAM THE STREETS OF CANADA TRYING TO STEAL MORE EQUIPMENT THAN COULD BE MOVED IN A DAY... THAT WOULD BE LIKE SAYING BEST BUY NEEDS TO KEEP THE LOCATION OF THEIR STORES SECRET SO NOBODY STEALS ANYTHING...NOBODY IS AFTER JASON BOYKO OTHER THAN PEOPLE HE STOLE FROM FIRST