As Thameslink aren't claiming dishonesty, hopefully there shouldn't be a lot to worry about. As others have said in similar cases, an employer may well regard hiding a relatively trivial conviction far more seriously than the offence itself.
It wouldn't completely surprise me if they dropped the case in view of the 6 days and the approaching deadline.
If there's anything you'd like to add or clarify to them, it would seem justifiable on the ground that you haven't had a lot of time to consider today's response.
First, two facts that are not in dispute: the police are statute barred from entering it onto the PNC, and a DBS check is based on what is recorded on the PNC.
The conclusion that I draw from these facts is that a Byelaw offence is effectively spent immediately and won't appear on a basic or standard DBS check.
I don't know about the police being statute barred (see NACRO, below), but in any case it's not the only relevant fact. It isn't just the police who add entries (see DaveNewcastle, below).
Although a standard DBS check is based on the PNC, an enhanced check adds what the police consider relevant. We might think this offence would be left out, even if the relevant police force already had, or obtained, the information.
The idea that a byelaw conviction "won't appear" in a standard DBS check (because it is not "recordable" on the PNC) seems overstated. I would say it is unwise to make this claim when giving advice.
But in any case there's a separate issue about what to disclose if asked.
"What is on the PNC" or "what might be revealed by a DBS check"
are different matters from
"whether the conviction is spent"
if we are talking about an employee's or applicant's legal duty to disclose when asked.
Now, you can say "it doesn't matter in practice" or "people will probably get away with it" but in giving advice, and on a public forum like this where other people may see the claims, it seems important to keep in mind, and try and explain, what the law actually allows.
NACRO said:
"We recommend:...That issues relating to police recording practices are resolved. For example, the inconsistent approach to placing non-recordable criminal record information on the PNC."
June 2018
https://3bx16p38bchl32s0e12di03h-wp.../06/Nacro-position-statement-on-filtering.pdf
DaveNewcastle said (2012):
"A Byelaws Offence successfully Prosecuted does not lead to a Criminal Record nor to an entry in the Police National Computer (PNC). However, Magistrates Courts deal with Railway ticketing irregularities along with other Criminal matters brought to them by the Police and CPS, so it does sometime arise that a PNC entry is made. (In the event that this does happen, they are notoriously difficult to remove or qualify once an entry is made)."
https://www.railforums.co.uk/threads/bye-law-no-18-2-consequence-query.61617/#post-1012885
......
2012:
"It appears to be a rather unpredictable outcome - if a Clerk's office just types in all of a day's cases without a second thought, then they'll all be recorded. If they notice that some are Byelaw matters with no Police or CPS involvement, then they might not.
I'd like to think that I am wrong and that there is more consistency than this, but that's not what I've found. Perhaps the outcome even varies in different parts of the Country, can anyone else provide other experiences?"
https://www.railforums.co.uk/threads/bye-law-no-18-2-consequence-query.61617/#post-1013365
2015:
"If the matter is tried in a Magistrates Court along with a number of Statutory Offences, then there is always a small risk that the Byelaw Offences will be typed in at the end of the day along with the Statutory Offences. It shouldn't happen, but has done in the past."
https://www.railforums.co.uk/thread...her-countries-such-as-us.112547/#post-2087784