Expand Each of these "instances of evidence" is a little story. Take your time with each of them. Make each of them into a paragraph, or even multiple paragraphs. This can get tedious if you stick them all after one another, so you may want to sprinkle them throughout the larger narrative to slowly establish the character as untrustworthy. In most stories, these kinds of incidents are not told in flashback, but as incidents in the story. It's much more interesting to have B observe A lying about his taste in food in the moment that to have B remembering it.
However, if you need to quickly and effectively establish that A is a sod, then this is not a good option.
Cut How much evidence do you really need? One instance of untrustworthy behavior is usually enough, especially if that's all we see of the character. Pick the most interesting instance, and tell that story in a single paragraph. You can hint that this behavior is not uncommon for the character by showing other people being unsurprised.
Use another character's voice This kind of listing of incidents from the past sounds like something you would say in an argument. Let A and B have a furious argument, and let A assert that he only made one misstep once, and he's still being punished for it. At that point B explodes with fury
Excuse me? Did you think I'd forgotten about the lies you told everybody about me? How you told everybody I was weak? Meanwhile telling all the adults how much you love travelling, and then expecting me to get you out of it when you're too scared to fly? Everything you say is two-faced! Just yesterday you were telling everybody about how you just looove great food. I've know you for two years and the only "restaurant" I've ever seen you in is a Burger King!
By embodying a character in the heat of the moment, you get much clearer constraints on what type of language is appropriate. An added benefit is that you are exploring and expanding the character of both A and B.