The German ran wide while trying to improve his lap time late in this afternoon's qualifying session, but the yellow flags that were brought out as a result of the incident prevented Mercedes teammate Lewis Hamilton from going faster.
The 28-year-old, who lives in Monte Carlo, told reporters: "No not [an ideal way to end qualifying.] I thought it was over, I thought the track would ramp up and someone else could beat my time. I'm happy it worked out. Pole at home is fantastic, it couldn't be better.
"Of course I'm sorry for Lewis I didn't know where he was. Of course yeah it's not great."
Race officials have confirmed that they are investigating the incident.