Well then the problem is with the legislators for micro-managing and making laws for every practical probability, rather than having common sense and allowing well-trained and intelligent police to use their judgement.
Police are well-trained and have good judgment (in general), IMHO. However, they cannot make up laws, nor should be ever allow them to.
If photography of police officers is illegal, then it is illegal. If it is legal, then it is legal. There is no room for an officer to 'make law' by saying, "Today, I decided that it is illegal to take my photo. Tomorrow, I may feel differently."
Imagine people arrested for breaking a law made up on the spot that didn't exist yesterday, and may not again tomorrow, on the basis that the police officer in question 'used his judgment'.
The 9-11 terrorists had access to the builder's plans for the WTC. Now that many of those documents have been secured from the general public, I would think the "power of photography" would be very useful, say in determining where charges might be placed on a bridge or to determine the volume of a subway tunnel. The engineer planning the attack need not be doing the scouting themselves and could indeed be half a world away....
Then shut down the interwebs - it is full of photos of bridges, tunnels, and tall buildings. Good Lord, the terrorists could simply watch "The History Channel" for detailed information on how famous bridges, tunnels, and tall buildings are designed, far more than could be obtained by a photo taken from street-level. And again, I must ask - what would a terrorist find useful about a photo of a policeman? They know what police officers look like.
Speaking only for myself, I refuse to live in fear and cower in the dark, seeking protection from thugs and hooligans, and urging that my liberties be taken away to protect me from these vague threats.
Even assuming that taking away personal liberties would be the correct way to protect us from terrorists - exactly when would these rights be restored? Even in the darkest days of the US Civil War, we knew that Habeus Corpus would be restored when the war was over. And it was. When exactly is the 'war on terror' over? There will ALWAYS be terrorists somewhere. Does that mean our liberties are redacted forever on that basis? Sorry, I won't go along with that. Arrest me now, I'm going to keep taking photos of whatever I want to take photos of.