@OP, such a standardised fine (let's say you were flashed 10km/h over the limit) is a non-issue here, no additional consequences, provided your friend pays within the time limit. Depending on where you're from it can be the preferred way to let your friend be the official driver because the actual driver may get additionally hit in the country of residence. Many countries have something like driver points, getting hit there has often a long lasting effect. Nothing keeps you from paying your friend for the fine informally.
This happened to me earlier this year. I leant my car to a relative for a few days. About one month after the car was returned I got a letter saying that there was speeding incident with my car (a few km/h over the limit) and the bill was SFR 40.- . It was a pure "administrative" matter so I paid it and the relative compensated me. Of course, if it was not so simple (say excessive speeding which has serious consequences) I'd have stated the particulars of the driver at the time of the incident and not involved myself further.
If I, as registered owner, cannot name someone else, then the assumption will be that I was driving.
In the specific incident I mentioned the relative had the car in his possession for 4 days and, from the date of the speeding incident and the location, it was clear.
Interesting would be when the owner claims that X was driving at the time and X denies it.
I guess that in a serious case, say extreme speeding which can carry a custodial sentence, the authorities would try to establish who was "responsible" for the car at the time (usually first the registered owner) and then if they had successfully discharged that "responsibility" onto someone else (hirer, borrower etc.). The person found ultimately "responsible" for the car will have to say either "Yes, I was driving" or "I don't know who was driving".
Unless the car was reported stolen sufficiently long in advance of the incident or there is some unusually creative defence, that is something better than having lent the keys of the car to a total stranger in a pub, not knowing who was driving will be more or less the same as admitting to driving.
Of course, this is slightly different from the case the OP has outlined.
There it will be clear who was claimed to have been driving at the time. Only that person will no longer be in the country and may never come back. So end of story ?
For everything else, there is no getting away. Friend got flashed years ago, tried to say it was his wife because he didn't want to lose his license. They got called to the police station, asked again "who was driving" and then got shown the picture clear as day. I remember the wife telling me "I could see what earrings I was wearing that day".
In practice there is no getting away.
And if we're discussing philosophically, I assume it's easy to remember who was driving your car when. Worst case scenario, check your Google Maps timeline, or that of people that borrowed the car around the time of the offense.
Maybe you don't remember, but Google surely does
Yes, I’m the exception to the rule.