Point taken, however....why the need to break into the place to steal a mysterious vial of whatever it was? (They've never told us.)
We don't even really know if the vial was taken from Richards Hall...
As some have pointed out in past threads they could've brought the vial into the building with them. All we know is that a "stoppered glass vial" was found on Boyce's person when he was searched that night/morning.
There are conflicting statements floating around over whether the vial was empty or not when it was found. Even if it was empty - as according to Sgt. Robinson of the OUPD - that doesn't necessarily mean it didn't contain something previously...
In thinking about this further my SPECULATIVE GUESS (provided that the vial was empty prior to and after the burglary) is that Boyce brought the vial in to the building hoping to fill it once inside and failed to achieve that due to the fact that the substances in the room they entered had been moved... That would make the most sense to me at this point. As I said, that's assuming that the vial was indeed empty and was not emptied at some time during the execution of their burglary "plan".