When do you feel that you are committed to the landing?
Only when the reverser's are selected in my company. Think about it .... you touch down at what 125-150kts .... you would normally be at about 80 kts at that point on the runway if taking off; so no problem going around from a speed/runway remaining POV. Deploying reverse thrust is a different kettle of fish however, in that re-establishing forward thrust is a variable and undefined feast.
That does lead however, to a grey area / captain's authority to override SOP's which may have featured here. A very tough call, should that be the case. Potentially hero or dead, and if it goes wrong, castigated by the 'book' and the legal profession who/which are here to defend corporate interests rather than yours.
The job of an airline pilot is,and esp Captain, [imho] not paid well-enough for the responsibility, in this day and age. I commend everyone to obtain legal insurance , pref through their IFALPA associate company. The way the system works is to try to shift corporate liability onto the individual.
I want to retire just asa I have enough money to live on ... lawyers with time and time on their side rule the world, and any decision you take can be questioned by people who can taek hours/days/weeks to review your decisions which affected real lives that you had to take in a minute or so.