According to the FBI's affidavit of Welch's statement, Comet Ping Pong has an outside freezer accessible through the rear exit. That is where the employee came from who went outside 'to the freezer in the alley' and had Welch's AR aimed pointed directed at him when he came back.

Can anyone show me the exit, the freezer, the alley and the regular route of an employee?

BTW researching this outside freezer issue I discovered there is most likely, at the very least, an underground garage beneath 5039 Con Ave. https://i.sli.mg/a/wnfcTT