Yes, it certainly can be. We don't recommend calling while driving. If it's an urgent road safety matter, you can legally call the Police on *555. If it is life-threatening, you should call 111.
You can ask a passenger to call, or you can use speed dial or 'siri' with a 'hands free kit'. Otherwise, wait until you get home or to work.
That's why we provide an easy to remember word number (0800 HOWSMY) and an on-line reporting service for when you get to home or work.