Depends where the burden applies.
Saying "Joe Blogs dodged a fare" probably isnt enough
"on X, a person identifying themselves as Joe blogs rode on Service K from Y to Z and was unable to provide a valid ticket to inspector I when confronted at time T" The Inspector can confirm that situation, as would the report written up, so there's at least a case without a defence.
At that point I would imagine the burden falls to the defendant to offer some defence, and the TOC to discredit that defence. eg "It wasn't me" - it falls to the TOC to prove it is that person who they stopped whom is in court.
Exactly.
At the specified place & point in time advised by a Summons to attend a Court hearing, the alleged evidence was put to the Magistrates, along with a certificate of service indicating that the Summons, witness statement and other relevant papers had been served upon the address given and confirmed (so far as practical ) as that of the defendant.
The Magistrates heard the prosecution case and with no response from the defendant to rebut that evidence, were satisfied that the defendant was guilty of the offence and a conviction was therefore recorded.
Very occasionally someone may become the victim of an impostor and may be convicted in error through this process, but that prosecution will have been brought in good faith.
If the conviction is challenged once known about and good evidence of the mistake is put to the prosecution and the Court, then the conviction will inevitably be overturned.
It's not a perfect system, but then little in life is I'm afraid.