I think the word should be more accurately, "rarely" rather than "sometimes."
And again, Gerry of all people should know the odds, since he spent considerable energy and time investigating child abductions, even meeting with experts in the United States.
It is disingenuous for the McCanns to say that any questions about their own involvement are "hurtful" and harm the search for Madeleine, when they themselves keep repeating that Madeleine is definitely not harmed (check the early interviews where they reiterate oddly that they know this) and that she is able to "give them their tuppence worth" implying that she is an equal in the relationship with the abductors, or even being "treated like a princess."
Those comments are more harmful than anything to motivation to search for Madeleine, because they reinforce the idea that Maddie is really not in any danger from her abductors.
We know from statistics that if she was abducted, just the opposite is true.
If the McCanns were indeed counseled by experts not to show emotion, then surely some expert could tell them also that they need to stop reinforcing the message that Madeleine is really, probably all right and being well cared for but by the way, she should come home.