Franz's worries were superfluous. Without needing any reminder from the Vienna Government, the Tsarist Government had already begun taking action.
However, their means were somewhat immature, probably because they were unprepared in advance, and the evidence produced by the Russians was not persuasive enough.
There were no movies at that time, makeup had not yet become one of the four great wicked arts, and there were no special effects to speak of, so it was somewhat difficult to fake photographs.
No, to be precise, the Tsarist Government had no concept of faking it at all.
The Berlin Government had launched a media offensive, and the Prussian Army at the front had been ordered to maintain military discipline long ago, so catching the Prussians red-handed at this time was naturally not easy.
The photographic evidence provided by the Tsarist Government had even been kindly sponsored by the Austrian Government.