If it was my DH being paraded around on Iranian television for the whole world to see I wouldn't give a toss if he was smoking or smiling because
A) I'd be so bloody pleased to see that he was alive
B) If he was smiling and smoking then he was obviously not being tortured in any way.
I think the world as a whole will realise what fine people we have in the Armed Forces, and probably wouldn't notice if they were smoking. Surely you wouldn't want to see them crying and looking distressed?
As to why they were complying with their captors, well none of them would be trained in interrogation techniques, they were ordinary sailors, it was probably better for them to comply, plus we don't know what they were told. if they had no access to Western Tv or consulate staff, they were maybe being told that they were definately in iranian waters and that the UK government had admitted it.