Engine really knocks after leakdown

The engine should not "kick-back" when you apply air. That cylinder was not at a true tdc. in that video I didn't see any indication of oil good pressure. Did you take the rocker shaft off to do the test? Is the shaft on correctly?? This wouldn't cause lifter tick but no oil pressure will. You can narrow it down to which valve it is by just touching each rocker. It'll let you know which one is sick.