How accurate are population reports?

[wolterse]

We are all aware of stories where a card is cracked & submitted to PSA/SGC three times b/c you or someone else didn't like the grade it received the first couple times. I can definitely sympathize. But how many times every day does this go on? I would suspect hundreds if not thousands of times over the course of a year. How many times has a card been undervalued based on an artificicially inflated pop because it or one like it has been submitted multiple times? Who knows? Prices may not be affected as often for low pop cards (around 10 - easier to keep track of) but there must be instances where a higher pop card (around or over 25) may have been submitted multiple times and realized lower prices because of an inaccurate pop report.

What does the board think about this? I can't think of any way to prevent this from happening and it's concerning as a collector.