I'm sitting here thinking it wouldn't be hard to wire the clock to stop on whistle. Put a sensor in ball, ref pushes button after he hands ball to inbounding player, it detects acceleration of throw in then starts clock on next (capacitive?) touch. (Ok probably it only transmits acceleration/touch and score table receiver does logic on that). As always human standby, if they hit start after transmitter starts clock or stop after whistle stops ignore it, but if they start/stop when a sensor missed it it accepts the human command and resumes logic. The programming seems easy here, the tech of not imbalancing the ball, durable for impact etc probably not that far off... As a bonus this system might help remove much of human skew on timing, but doesn't help refs slow to whistle etc.
On the surface this isn't news for nerds.. But really with a bit of imagination it could be!