[pinko]

This implies that these things must throw false alarms with some regularity, otherwise this would have been a huge red flag and they wouldn't have hesitated to follow up immediately.

[danielweber]

This seems likely. Even if you get him on the phone, you could have an officer drive by sometime in the next day to visually inspect that the ankle bracelet is still there.

(Of course I would get a second bracelet and strap a dummy one to my leg to show to the officer. Officer would need some way of verifying he's seeing the right one.)