Having just spent 11 hour days score running, XC scoring isn’t always easy.
Each JJ may have a radio, and XC scoring is listening to multiple people calling in fences at the same time. Add in human error, people inexperienced with using radios, bad signal, batteries dying, etc. Then a score running picks up the paper score sheets which are hopefully clearly marked and haven’t disintegrated due to rain. The paper sheets are “official” but there can be discrepancies and in some cases you might not have a sheet like if the JJ loses it, it blows away, or falls apart in bad weather. Mistakes absolutely happen, especially when eventing relies so strongly on volunteers.
I have seen riders miss a fence, jump the wrong fence, or have clear stops or backward steps and not even remember it. I wouldn’t necessarily jump to bad sportsmanship. I have also seen the TD driving out to fences to gain clarification from a JJ who is confused about what they saw.
If someone feels a fence was recorded wrong they can ask to speak to the TD. Riders can be very heated about this and I’m glad TD is a paid position but they really do the research for the riders. I think riders should also be aware that TDs can be pretty busy and can’t always instantly respond.