Well, if we were to believe their account we just have to run through the good ol' checklist:
1. Are they stupid? Could they be easily tricked?
No, airline pilots are generally expected to be capable individuals.
2. Have they claimed such things in the past?
Presumably not, otherwise that would have jumped up in the report.
3. Are they the type of people who would look for the extraordinary in the merely 'odd'?
Who knows? It's a big group of people who don't seem to be too closely related, but who can tell?
4. Did they have more to gain by telling than they had to lose?
Considering they're probably a laughing stock at this moment among the majority of the staff of the airport, their family and their friends, I'd say no. There are some pretty strange things on this Earth already, without adding UFOs. I'm not sure what they saw but it is interestd their friends, I'd say they didn't. They must be feeling pretty awful by now..
Conclusion? Maybe it's not as ridiculous as it seems. I certainly believe they saw something incredible, something they all thought was a UFO, but whether that was the case will probably never be proven. The airport will do its damned best to cover it up as an airport doesn't want people to think that anything - much less a UFO - might take to hovering in the way of its planes.
Odd, though.