Rather than plausible deniability he probably means mitigating circumstances. For example, he was
- Coerced
- Impaired through drink or drugs
- Played a minor role in the offence (he didn’t cut the lock, but he did ride it away)
- Culpability of the victim (the bike was left unlocked on the offenders property)
- He had a family emergency and ‘borrowed’ the bike, with the intention of returning it.
- Unfit mental state, wife left him, hamster died etc etc.

If you a caught stealing a bike you can’t plausibly deny stealing it but you can offer a mitigation in the hope of a lesser punishment.

Dont think the punishment would vary but the consequences may vary because he is on a 'guest' permit and not a citizen.....btw, this applies in most other countries.....

I would suggest that we avoid offering creative ways to explain what seems like a deliberate action....that his lawyer can do....we dont need to do it and we should avoid that on this forum.....if you can do the crime, you should be willing to do the time.....

Its a good question and it surprised me of course. I would be doubly shocked if he was a bike stealer. I'm assuming he is just a reckless idiot. I didnt feel like it was my position to questions. Not at first anyway!

It was not real stealing. It was a mistake

Even if guilty, it probably won't lead to a criminal record for the very reason you state. Fine has to be 6k plus IIRC.

What kind of bike were you trying to steal and why, OP?

How'd you get caught?

There are essentially three categories of prosecution:

• Verbrechen: felonies, serious crimes;
• Vergehen: misdemeanours;
• Übertretungen: transgressions, very mild violations of the law.

Theft at the level of the OP's friend will probably be treated as an Übertretung, attracting a fine, maybe also some community service. As long as the fine is less than CHF 5,000, there shouldn't be an entry in the criminal record.

Convictions for Verbrechen (felonies) and Vergehen (higher level misdemeanours) result in an automatic criminal record. Additionally, punishment by a fine over CHF 5,000, community service >180 hours, or a prison sentence of a year or more—even if only for an Übertretung—all result in an entry in the criminal record.

An entry is made in the criminal record for Verbrechen right at the start, when proceedings are still pending. (Theft of one bicycle is gemerally not prosecuted as a Verbrechen.) This is because almost all convictions in Switzerland occur automatically, without a court case. Basically, if you are charged, you will initially be convicted. If you don't like that outcome, you need to appeal. Note, however, that pending felony proceedings do not appear in the extract of the criminal record—the extract that an individual can request for employment purposes, for example—but do appear in the complete record which can be viewed by certain governmental departments, including Immigration.

Entries in the criminal record remain for a minimum of ten years. They may be erased from the extract in as few as two years, but they remain visible to those governmental departments as long as they remain on the complete record.

So, back to the OP and his friend. The likely alternative outcomes are:

• Prosecuted as an Übertretung: no criminal record unless an epically huge fine is imposed;
• Prosecuted as a Vergehen: automatic criminal record for at least ten years, regardless of the penalty imposed.