The chances of this being real are basically zero, or Russia would be getting double agented, and reverse intelling themselves, out the arse. Instead all we get are attempts to connect random events, of which there are endless viable suspects, to Russia.
It's fair to say that if one jumps in the middle of a fight, they should expect to get punched, but it's also fair to say that for now Russia has been avoiding throwing much in the way of punches.
Here's the article in Germany about the incident: https://www.rtl.de/news/russische-spionage-rtl-reporter-unde...
How does some chump who gets paid to stick potatoes into tailpipes* become a double agent? Being a double agent requires the ability to hurt the side you're ostensibly working for. The potato guy can show Telegram chats where a guy called Alexey, or maybe an entirely non-Russian name, gave him a job.
* That actually happened. It was a false flag operation to discredit the Greens (party).