Many facts being disputed can be either true or false depending on interpretation, so the interpretation decides if the person is a liar or not.
For example, "if you like your doctor, you can keep him/her" is true if you include paying for him/her yourself but false if you limit it to what insurance covers.
This is where sites like politifact really get wiggle room to change the narrative. Just interpret the meaning in the most favorable strictness for who you want to call a liar.
I honestly can't tell if the people who defend politifact are unscrupulous or genuine. It's infuriating that, no matter what is said, nothing is ever accepted.
For example, "if you like your doctor, you can keep him/her" is true if you include paying for him/her yourself but false if you limit it to what insurance covers.
This is where sites like politifact really get wiggle room to change the narrative. Just interpret the meaning in the most favorable strictness for who you want to call a liar.