This guy had to fight his bank for 8 years after a known criminal took up a mortgage in his name. There was plenty of evidence for identity theft, including an admission from the scammer himself, who was on the run. The bank didn't care about any of this and kept pursuing the case.
In my opinion, the bank targeted the victim because the perpetrator was gone. The greedy bastards wanted their money back, and pursuing the victim had the highest chance of success.