Eager for the chance to work on the vehicle further, Batman deliberately sabotaged the engine and claimed that Roxy's actions were to blame; a sharp-eyed Alfred sees through the ruse, but decides to let Bruce have his fun regardless.
Batman was keen to deepen his work on the vehicle and deliberately damaged its engine, pinning the blame on Roxy. Despite noticing through his sharp eyesight, Alfred decided to overlook this and allow Bruce to continue as planned.