Theft Description

Two men on a scooter stole from outside my house (in front of my CCTV) using a loud lock grinder that woke me up. Whilst I shouted at them they pushed it backwards over gravel, started the engine first time and drove it away. I had disconnected the battery whilst away (to charge it) and reconnected it the day before. How did they start the scooter without the key fob?