Doubting what someone says is an expression of disrespect, especially when you publicly express it repeatedly.
It is in material effect, no matter the intent, to cause those around to infer additional doubt and suspicion on that person.
It is in this way definitionally, to treat someone as suspect.
And then to repeatedly do it?
That is an attack.
If I saw this happen in front of me, I would lose respect for the person who took that but did not respond with a slap.
If the person so slapped asked me "why did they slap me" I would respond "because you attacked their honesty, for no good reason, with no proof of anything but your own haughtiness, in public. You should be glad that's all they did after you attacked them."
Thank you for alerting us to your propensity for physical violence.