Not knowing any background of the dog's previous training these are my observation:
-dog enters the circle on #1 unfocused looking at and sniffing the ground on #2 dog enter focused and attentive anticipating being worked.
- dog's gait is faster and happier without the collar,
- dog's delivery less controlled without collar
- the dog has a decreased obedience level without a collar
- handler sends dog faster without a collar
The dog is perfectly capable of the retrieves. IMHO the difference in the videos is the quality of line manners.
Placing a collar on a dog is in and of itself a cue, its time to work. It would interesting to see the dog's reaction to heel and sit several times as walking into the circle w/o a collar to identify work time.
What happens with this dog on remote recall without retrieving? Do you teach precision heeling before CC.