The Antwerp police had to send the ticket to the Netherlands, because that's where the car was registered. Which took some time to go through the political process.
But the car was a lease, so the police had to re-send the ticket to the company I was working for. Which took some more time.
Then the company pointed out that I lived in Brussels, so the police had to re-send the ticket again. Which took even more time.
I finally got the ticket more than a year after the event, and I went down to the local police station to find out what I had to do.
The local Brussels police took the ticket and looked it up in their systems, and finally told me that the ticket was expired and had not been sent to me in time (there is apparently a one year grace period), and so I didn't need to do anything at all.