Time of Flight sensor design
You're assuming that timing accuracy is the inverse of bandwidth, but this is not so.  How accurately you can measure something is not directly related to how fast it changes.  For example, imagine you had a incredibly low noise, exactly reproducible 1 Hz bandwidth sensor.  You could measure the shape of that 1 Hz signal extremely accurately and localize when it happened very accurately, probably down to at least microseconds.  In that case you would have accuracy thousands of times better than the inverse of bandwidth.
The SPADs in that TOF sensor work on this principle.  They are made lithographically to have very, very reproducible single photon response with a very clean rise even though their 3dB bandwidth is very limited (10s of MHz).  The hardware then carefully localizes the exact edge of that rise time and calculates exactly when the photon arrived.