There are different ways to measure reaction time. Circumstance is important.
Reaction to unreasonable, unexpected events will be very slow due to processing and trying to understand what happens and how to respond. Examples, you are a racecar driver, participating in a race, you're driving your car on a racetrack in a peaceful country.
An armed attack: Slow reaction time, identifying the situation will take a long time, selecting an appropriate response will take longer.
A kid running into the road on the far side of the audience stands: Faster.
Kid running into the road near the audience: Faster.
Car you're tailing braking with no turn to come: Faster.
Crashed car behind a turn with bad overview: Faster.
Guy you're slipstreaming braking before a turn: Even faster.
For rhythm games, you anticipate and time the events, and so you can say these are no longer reactions, but actions.
In the git context, where you typed something wrong, the lines are blurred, you're processing while you're acting, you're typing while you're evaluating what you're typing, first line of defence is you're feeling/sensing that you typed wrong, either from the feedback that your fingers touched too many keys, or that you felt the rhythm of your typing was wrong, at least for me, this happens way faster than my visual input. I'm making errors as I type this, and they're corrected faster than I can really read it, sometimes I get it wrong and deleted a word that was correct. But still, watching people type, I see this all the time, they're not watching and thinking about the letters exclusively, there's something going on in their minds at the same time. 100 ms is a rather wide window in this context.
Also, that said, we did a lot of experiments at work with a reaction time tester, most people got less than 70 ms after practice (a led lights up at a random interval between 2 and 10 seconds)