I agree. This is a good question to ask of ourselves as we broaden our diving experiences and consider our roles underwater. It's satisfying to see the posts of other divers who step back and think about what kind of role they want to play as they visit our oceans, and I mean that both ways...those who might touch too much and might now refrain, and those who don't touch at all who might see a time when it might not be harmful.
As for me, I'll continue to hold off on the unnecessary handling. While I know that there are some situations in which touching the fawna might not be outright harmful, I'll still continue a hands-off policy for yet one other reason...the example it sets. I'm a professional educator, and I'm always mindful that others are watching. While I might see a situation in which picking up a critter is harmless, does that diver watching me know why it's okay in that situation and not in another? If I can't be sure, then I'll keep my hands to myself.
I can only refer to some things I've witnessed and even have on tape. I watched a fellow grab a resting nurse shark until it fled, and later that same person pushed a feeding turtle off its feeding area. Yes, I got that on video, and I use it to show students and divers what NOT to do, because I don't think there is any question that this is something that should be discouraged.
As for the regs in the Flower Gardens...Walter, I dive with those folks (staff members at the NMS) and they have conditioned me not to touch just about anything down there. It might not be against the rules to tickle a cowfish, but they sure don't like to see you do it. They've also amended one of their own promo videos that once showed a fellow talking about petting a manta. The written regulations are one thing, but their example is another.