I'm not even sure it's fair to "blame" the lab or anybody else on this one. Apparently the fingerprints were all extremely similar such that a few different sets of expert eyes all were fooled for a while.
In the end though, the fingerprint differences were discovered and this guy's prints were excluded. That's not a mistake, that's just how investigations sometimes work. Yes, one can say that they were mistakenly identified... but it wasn't a procedural or process error-- it was a re-analysis of prints that at first genuinely appeared to match.
To call any of this a "problem" at the FBI suggests that the FBI or anybody else in the investigation should have acted any differently given the information they had at the time. They should not have.
What bothers me the most about this is a US citizen was "secretly held as a material witness for two weeks". This stuff isn't supposed to happen in America.