They didn't even get on the pad, so it was a site to site transport that could have been initiated from anywhere. They just came to transporter room 3 out of spite. 😆
They were planning on asking a transporter chief to beam them to the planet, but they saw O'Brien was there and was like, "fuck that guy. Double dumbass on him."
If the computer can do transports, why is O'Brian even in the transporter room? Just to suffer? Fucker doesn't even get a chair. Stare at the wall for 8 hours, standing straight because your can't even lean.