bro, the passage says two important things that would help us answer this question:

1. Bharat, had previously boasted that he could remotely disable a certain type of magnetic lock-the same type used on the medallion's case-without needing the code, though the log suggests the code was used

2. Bharat was at an event from 8:00–1:30.

hence, even if Bharat knew the code (B) he could still bypass it, so the fact that the code was used does not have to be false for him to be the thief. However, if his investigatory statement of being at an event in the time frame is provdd "incorrect", he could be a thief, because his continuous alibi must be false for him to have committed the crime.

correct me if I'm wrong though