A heroic bystander was caught on camera confronting the Australian mall slasher as he charged up an escalator during Saturday’s deadly rampage. A brief video clip shows the unidentified defender wielding a retractable-barrier post against the attacker at the top of the escalator in the Westfield Bondi Junction shopping center in Sydney, according to Sky News Australia. The killer, who was reportedly holding a large knife, stopped in his tracks as the other man, apparently a shopper, fearlessly took two steps toward him on the stairs, which weren’t moving. The video, about three seconds long, w…