Continuity mistake: When Billy and Sicknote go upstairs after their encounter with Pitbull, they go upstairs to change into uniform. The camera follows them upstairs. The appliance bay has no other firefighters present. When the camera pans back down, a full roll-call is taking place in the appliance bay, including Billy and Sicknote who just went upstairs to change few seconds earlier. This was probably done intentionally but it sure does look ridiculous.
More mistakes in London's Burning