Great job of handling a potentially violent situation. You did good my friend. Sometimes the hardest thing to do is to swallow ones pride. I'd bet anything your daughter being there had a whole lot to do with your reaction.
In other threads I have given my opinion of ankle carry. I have absoloutly no use for it. I believe it to be dangerous.
Another interesting point that you bring up is the fact that you left your EDC home... after all what could happen at an ice cream shop? I have several times questioned why so many people opt. for a full sized service pistol for EDC. Then jump through hoops trying to conceal it. A bigger gun can be an annoyance. And is often left home. I personally dont subscribe to the terminology of a back-up gun (BUG). Except for police, security, high risk situations. As a cop it's mostly refered to as an off duty, or a second gun. Back up is more a method, or a mission for the second gun.
Again carrying the service pistol/revolver can be a pain and all too often leads to carrying no gun at all. I propose the concept of a EDC gun. More comfortable to carry, and easier to conceal as the primary EDC. In the civilian non-threat world the service sized pistol would become the second gun shoud the carrier feel the need to up-gun.
All based on my own personal experience, and training.
P/S I personally and very strongly recoment that anyone who carries for self defense own at least one service sized pistol, and one EDC smaller carry gun.