Meh, judicial crap question.
If a record of an infraction of... law... is sealed from public scrutiny should the violation be dismissed?
One of the legal concepts of western law is "public good". Judges can and do consider the public good when interpreting a point of law. This is often the tipping point when a law or legal application of a law is ambiguous.
This leads to the question, is the public good better served by maintaining the status quo, or by making the change you suggest? We can assume the guilt of the person who violated the law is established and the sentence has been applied, whatever it was. The law allows all of this to be concealed in some cases.
Who benefits from this? Apparently, the criminal. If the violation is concealed because it was a first offense, dismissing the charge could lead to an endless series of repeat first offenses.
I remember a scandal not far from where I live. Judges generally treat a first offense DUI very leniently, if there are no aggravating factors. The accused can submit to therapy and education, and if they stay clean for a period of time, the conviction could be expunged from their record. This depends upon the Judge being made aware of any previous convictions. The procedure in this particular jurisdiction was for the prosecutor to staple a copy of any previous DUI convictions to the presentencing paperwork submitted to the Judge.
That's where the problem arose. The collecting of records and the stapling was performed by clerical staff in the prosecutors office. There was a certain prosecutor who would remove the copies before submitting them. This resulted in quite a few people appearing in court after multiple DUI convictions, and treated as a first offender in each case. This happened often enough, questions were raised. All cases led back to the same prosecutor and he blamed the clerks. Blaming clerks for bad paperwork is always a bad idea. When the questionable presentencing reports were pulled from the files, all had staple holes in them.