Another woman stood in front of her to protect her form Coulson.
But during the exchange, Coulson flicked his hand at the victim, which resulted in blood landing on her face, the court heard.
The woman was "terrified" that she might have contracted Hepatitis C during the assault, which Coulson pleaded guilty to.
The court heard today that the victim has undergone blood tests to see if she has contracted the virus.
Defence counsel Elizabeth Bulger said Coulson wants to apologise to the victim and find out whether she has tested positive, but has been unable to do so because of his non-contact bail conditions.
Judge Alistair Garland told the court that if she has tested positive then an apology "won't be quite sufficient".
He adjourned sentencing until April 13 for the blood test results to be provided to the court so that he can determine the seriousness of the assault.