The lab screw up. Didn't you read the story before you posted? (Sometimes I don't either).
So the lab should have just ignored fingerprints that appeared to match?
That would have been a screw up deserving of headlines. As it was the fingerprints were very close and matched in enough ways to be worth pursuing. Later they found out that the prints, while close, were not in fact a match.
What should they have done? Just ignored it then?
Is that a trick question?