As has been said, in the end changing the dates on these cattle makes very little difference in the end when they are mature animals.
I remember showing some ???? years ago in 4-H and FFA it seemed like all the judges placed a class from the tallest to the shortest animal. Then when they gave the reasons it seemed like that many times the 3 to 5th place animal was always the animal that they liked the best and the only reason they didn't place higher and if they could change one thing about them it would be that they had more frame.
While frame is important, other qualities have to be there as well.
Are breeding dates, due dates, etc. not checked. Are dates of birth within a valid range? If one animal is turned in with a younger date of birth, then the next calf would need to be as well. It looks to me like that something would possibly show up, maybe not. I know that in submitting records to the USDA on dairy cattle that if a birth date is out of range I get a report. The report looks at the age of the bull, the age of the cow and also if any siblings have been reported. If a calve is in a herd and getting a genetic evaluation, they can't have one if there are not enough contemporaries or if they are not in a birth range within 60 - 90 days.
Whole herd reporting could help on some of this, but also many with club calves do not register their animals either. They just say what the pedigree is and who it goes back to. Do they???