If you use the term GMT...that’s UK time...that 2:30 GMT would be 3:30 local time in Germany.
Focus (the German news magazine) put this at 4:30 AM. Like you write though...there at least one or two other news sites which it earlier. If you look at the ‘Grey’ (name of the disco)....on Goggle Earth....it’s appears like some old warehouse or grocery store building. Within the city limits.
I believe that due to Summer Time (1 hour ahead of “regular time”) the difference to GMT (”absolute time”) is currently 2 hours. That would make it fit.