That, was what would have made it 'illegal' for me mate? The tackler actually got into a good body position, low, aiming for the shin/knee area but............... those flying boots?????? Alternately, had the tackler aimed for the midriff, I reckon momentum could have resulted in a possible tip-tackle? Who then would have been at fault? It's such a rare occurrence, it's hard to think what hard & fast rule could apply? For me, I'd have considered it a dangerous/illegal move and I'd be inclined to penalise it? (No more than that though?)