Different “sounding” perhaps, but they’re two forms of the same name, Diego.
Just want to throw an idea out there, so bear with me... I have contacts on my phone that have their reasons for wanting to stay out of the sight of the police (nothing too dodge, they’re just horticulturalists

) ... First thing they tell you to do is save their number under a different name. If you don’t know them so well, you might give them a similar sounding name to their own so you remember...
If you look at my current contact list, you’ll see a number for a “Nathan West”. I don’t know any Nathan Wests, but for a long while I could never remember my online banking details, and I bank with Nationwide... See where I’m going with this?
Also, him breaking down in tears during questioning and then admitting he lost the keys? I was a teenage girl once, I know that game. You cry and admit to a lesser crime so it makes your denial to the first more believable.
Anyway, I’m sure the German’s have thought of all that and have been through these files with a fine toothed comb.