Starting to look like another of the web's urban legends to me. Thanks for clarifying that.That claim by the Lee Parks glove company seemed rather dubious to me, so I did some research.
I was unable to find any conclusive evidence that carbon fiber knuckles can cause lacerations to the hands.
However, the knuckles have been known to shatter, especially in cheaper gear, but because they are not in direct contact with the skin, the probability of lacerations is extremely small...
Of course anything could happen in the violence of an crash, so it cannot be completely ruled out.
The only thing I was able to find was other motorcycle forums referencing the claims made by the Lee Parks glove company.
All "evidence" is either anecdotal or being used to sell Lee Parks gloves.
I even looked up the accident Ken Meese (supposedly the guy holding up his scared hand) suffered during the 2011 Iron Butt Rally. Here is a quote from his website, "In 2011, less than 24 hours from the finish, he was in the lead to win…but a coyote had other plans. Ken ended up with a shredded spleen that had to be removed, collapsed lung, cracked ribs, broken left scapula, and broken bones/snapped tendons in his right hand. But from the time he woke up, his thoughts were on recovery and how he could get back into fighting shape for 2013."
It says nothing about shattered carbon fiber knuckles causing the injuries.
Make your own conclusion, but to me it looks like good marketing.