Well Rock, Like SB, I used to get called a lot to help track deer and like you I have found that MOST of the hard to track deer have been from poor penetration or marginal hits nicking the liver or some such. BUT, there have been quite a few that I had a hard time finding because of those 2 blade expandable heads that just sealed right up. Lot of people like those heads because they get accuracy alongside of their field tips. Sometimes those heads lay a deer open really well while other times those up and down slices just fat seal up and don't leak at all. Deer still died but without a trail they can be a mite difficult to find. So yes I have seen several deer that were really hard to track even with perfect passthrough lung shots. But never from a 3 blade or one of those hybrid jobs with bleeder blades. Those holes don't fat seal.
SB you've been in the woods a long time and should know better than to take out the heart with Bow! Lung shots! You then don't have to wait for the cavity to fill up before leaking blood leaving a trail! No heart=nothing pumping blood! Lung shots give you good spray every time they try to breath. Plus, I've found they go down much quicker from double lung and for some odd reason they tend to circle more so than straight flat out run when lung hit. Never have figured out why but danged if I haven't seen it happen a lot.