Carefully

Zane used his suit jacket wrapped around his hand to punch out the rest of the glass that was remaining around the window in order to decrease the risk of cutting himself. 

He was also going to need it to be as clean as possible if he tried to get anyone else out as well. 

Lifting himself carefully, he gripped the ledge of the car door window where it looked like the least amount of glass was left. He could handle a few cuts on his hands so long as they weren't too deep. 

Everything that the mafia boss did was with careful precision. He had to move quickly but he needed to watch out for his injuries as well as make sure that there was no one outside the car. Based upon the time that his watch broke at it, he had only been out for a total of fifteen minutes. 

If whoever was responsible for what happened was going to spend someone to check and make sure that the job had been 'done', it would likely be within the next fifteen to thirty minutes.