Cast Performance is definately not LBT, nor affilitated with LBT in any way, though one would think they were by reading what they say of themselves.
If you have read well about my displacement Velocity formula DV, you'll know that a DV of 100 to 125 is optimum for fastest kills. So if a bullet that is too heavy is shot at too low a speed, it won't deliver enough DV or wound diameter to cause rapid blood loss and quick kills.
Trying to recreate how the bullet passed through the deer, it appears you shot from a tree stand, missed the spine and had the bullet exit on the same side down the shoulder and leg, which means, if I'm reading you right: The bullet probably didn't take out much lung, and only on one side. If my guess is right, it cancelled out half the deers breathing, or less, but didn't go through the main arteries between the lungs, and may not have taken out even the heaviest part of the lung that was hit. The impact close to the spine would incapacitate for a few seconds, but slow bleeding and fairly adaquate air to an uninjured lung, allowed him to get up when the shock wore off.
This is all a bunch of second guessing, in an attempt to give an accurate answer. A one inch diameter or larger wound, not to exceed 1 3/8 inch diameter, passing through both lungs and or the major arteries between them, almost always anchors the animal where it stands. In my experiance, autopsy of animals which run after getting a good sized wound, actually show somewhat minor wounding in the critical organs and major blood system. Regarding the LBT softnose method. It is good, but not needed if DV is held between 100 and 125 and shots are half decently placed.