We used to get regular calls from concerned members of the public on particularly lovely mornings, like this morning was. When these calls are made 'with good intent' we used to investigate to make sure that there was in fact no LOS, then call them back, thanking them for their concern, but assuring them that following an inquiry, there was nothing to worry about. We've now got a whole department who deal with these and other issues such as noise, so we don't get so much now.
I always treat calls made with good intent that report anything safety related seriously; every now and again someone spots something that really matters, like bits falling off aircraft. I personally value contributions from spotters, they tend to know what they're talking about and can at least give you the reggie of the subject a/c! Of course, the FIRST thing you do is ask the caller for a name, address and contact phone number, then say you're going to call them back for more info. If the line suddenly goes dead, you got a hoaxer.
Now, as to cynically punting around a photo like that to journos desperate for an easy story with which to frighten a gullible public, no excuses, pretty poor show, they shouldn't be allowed to get away with it. The DHL alleged quote didn't help, either, failing to mention the 1,000' vertical separation (or maybe they did and the journos deliberately left it out so as not to reduce the impact of their story).
Cheers,
TheOddOne