This summary is not the rule. The rule text controls.
If someone pays for another person's medical bills or offers to cover the cost of damaged property after an accident, that act cannot be used in court as proof that they caused the accident. This applies to actual payments, promises to pay, and offers to pay.
The idea behind this rule is simple. People should feel free to help others after an accident without worrying that their kindness will be used against them later. If a driver pays for the other person's car repairs or hospital bill, that alone does not mean the driver admitted fault. It just means they wanted to help.
This rule only blocks the evidence from being used to prove fault. A judge might still allow it to come into evidence for a different reason, as long as it's not being used to show who caused the injury or damage.