My experiences would differ from this on the most part. Both deer I shot with a .30 carbine had "bleeder" exit wounds on the off side...yes the entrance points had a small blood spot on the hair but did close up before much came out...but I have had the same with many dozens of deer shot with a plethora of different "high speed" rifles from 6 Mill to 300 WM.
The biggest difference in your post & my experience is in using the 45-70. I have shot many deer with a 45-70, 38-56 type BP speed slug (under 1300 fps). The old adage is entirely true...."eat right up to the hole". The fact is they act exactly as you describe the .30 carbine will...but would anyone argue the "killing prowess" of a 45-70. This year I plan on using a 260 gr .379 slug for my deer...not from an H&H but from a 38-55 at 1350 fps.
The one thing I will give you tho , with a .30 carb, shot placement is very critical...if the hunter cant hit a vehicle licence plate sized target ( the aprox area of rib cage behind the shoulder) every time at the range he's shooting too, he shouldn't be using a carb. A shoulder shot (heavy bone & 3 " of meat to penetrate before it gets to the "killing stuff") with a carb. will probably involve a lot of hoofing & tracking before recovery happens.