All I can say for certain about a deer "jumping the string" is that I have watched a buck at about 30 yards drop enough for an arrow from the Vixen I was shooting to pass just over his back. This happened my first year of hunting with an Excalibur, and I was using heavy arrows and only getting about 260fps velocity. I had a max-zone scope on the bow and the crosshair was zeroed at 20 yards. The other marks did not work out to 10 yard increments, but were on at about 27-34-40 yards as I remember. The buck was 30 or 31 yards away, and I held the 34 yard mark for a top of the heart shot, which put the 27 yard mark high in the lungs. The arrow should have been about half way between those marks at that distance. This was my first Excalibur and I had been shooting every day for a couple months. I had learned to watch the arrow through the scope until it hit the target (follow through), and I was able to hit a pop can size target every shot out to 40 yards. I had already shot a deer or two (not certain what the limit was that season or how many i killed, but I know I already had shot one doe from that same stand). I was well practiced, I had already killed a deer and was not suffering from "buck fever" on the shot! I put the scope on the buck (small rack so I wasn't too excited) and I squeezed the trigger. The bow fired and I watched the buck drop as the arrow was in flight. The arrow passed just over his back - a clean miss!
I did not flinch - miss - or "blow" the shot. The shot was perfect! The arrow went exaclty where it was aimed, but the buck was not there when it arrived! I probably did aim too high, I should have held lower, but if I had it would have been a very high hit, possibly spine or higher. I'm glad i missed completely, but I'll gurantee you that buck DID "jump the string"! It may have been the noise, or he may have seen the limbs move when i shot, but he did move probably close to 8" before the arrow got to him!
I have also watched a deer at 31 or 32 yards that never even flinched until the arrow was there, which goes to add meaning to the "predictably unpredictable" theory.
Just my personal experiences, but I have been hunting for about half a century now and I have gained most of my skills by learning from the mistakes along the way. As far as I'm concerned a deer that is past 30 yards is not a sure thing even with my 300fps Phoenix. My last 3 deer kills(last season and this one) have all been less than 10 yards, and as long as I can get that close why take chances on long shots? I may not get to shoot at every deer that comes along, but the ones I do shoot at are in serious trouble.
