Don't be so hard on the rag, they did get one bit right. “The industry markets their product as a way to reduce harm and to help people to stop smoking tobacco cigarettes."
So basically they tested people who never use nicotine and found an increase in blood pressure, heart rate and arterial stiffness... They note "There was no such effect in the volunteers who smoked the e-cigarettes without nicotine" this is oddly sensationalistic for the Guardian.