I believe Hawkeye was developed to determine position...

...and not to count time. It is used in tennis, for example, to determine of a ball is in or out--that's a positional issue that a high-frame-rate system like Hawkeye was designed to work on.

Hawkeye was not designed, I believe, to be a digital; timer the way the game clock is, where time is simply counted down sequentially. I read somewhere earlier that Hawkeye gets synced to the game clock and then interim timings of less than a second are based on frame rate algorithms. There is almost certainly a margin of error to this; Hawkeye admits to a 5% error margin (3.6mm versus the diameter of a tennis ball at 67mm) for in and out calls. Who knows what sort of error could creep into the attempt to use Hawkeye as a timer, rather than as a positional analyst.

The rule book says that the game clock keeps time, and tenths of a second aren't to be counted. So how did they manage to use an app designed to determine position to supercede the evidence of the game clock?