David Halaifonua destroys Cory Allen with huge LEGAL hit

David Halaifonua delivered one of the more powerful tackles you're likely to see as he nearly knocked the boots off Cory Allen when Tonga and Wales met in Auckland. While the hit was reviewed, the TMO ruled that it was completely legal and play resumed.    Allen came on just after half time as a substitute for Alex Cuthbert and minutes later got a chance to streak down the wing. However, before he could get too far, he was met by lurking fullback Halaifonua. It was a shot that left Allen dead in his tracks, with his head snapped back like a ragdoll. Allen went down hard and was then attende…