The Portuguese faces possible action from the Football Association, including a fine and potential ban, after being dismissed for supposedly stepping outside of his technical area.
Sky Sports News reports that Mourinho is still in the dark as to whether he will be punished for the incident, but the 54-year-old - sanctioned twice by the FA last season - is unsure exactly what he was penalised for at St Mary's Stadium.
"I don't know," he told reporters when asked to explain why he got the ticking off from Pawson. "I don't know. Craig told me to leave, and I left."
Mourinho was given a touchline ban and a £50,000 fine for two separate incidents last November, which may be taken into account when the FA weighs up this latest incident.