Let's not lose sight of the fact that, provided the operator does not abuse the applicable legal process, the OP is not at risk of prosecution: evidently this must be the case of a penalty fare having been issued as two appeals against it have already been adjudicated. So, magistrates will not be involved in a determination of whether opening a gate constitutes authority to travel on a ticket for a different date. Furthermore, the burden of proof will not lie on the OP to prove that such authority to travel was given by way of defence to a criminal charge.
I see no harm in the OP raising, as one of the grounds of a Final Appeal under Regulation 18 of the Railways (Penalty Fares) Regulations 2018, the argument that being permitted to pass through the gateline prior to train travel constituted permission given by “a person acting or purporting to act on behalf of the operator” to travel on such train without having a travel ticket, thereby making the case one captured by Regulation 6(2), and consequently one in which Regulation 6(1) provides that a penalty fare must not be charged. In turn that would make the case one in which an applicable ground of appeal is that “the penalty fare was not charged in accordance with the requirements of these Regulations” (Regulation 16(3)(a)), and as such an admissible ground of appeal to the Final Appeal panel under Regulation 18(2)(b).
It may well be important to establish exactly what submissions the OP has made in the First and Second Stage Appeals, and how (if at all) the appeal handler has responded to them. This is particularly true of factual assertions made by the OP in the First Stage appeal, because the stipulation in Regulation 16(4) that “it is for the operator on whose behalf the penalty fare was charged to provide evidence that reasonably demonstrates that any fact described by the appellant in relation to any of those matters
(i.e. “matters specified in paragraph (5)”) is not true” may
only apply to such matters as are asserted by an appellant in a First Stage appeal. This is so because there is no stipulation corresponding to that contained in Regulation 16(4) that is expressed to apply to a Second Stage Appeal under Regulation 17 or a Final Appeal under Regulation 18. The ramifications of this difference may call for further consideration.
Even if the Regulation 16(3)(a) ground of appeal is treated as being of dubious merit, an additional/alternative way of approaching the case is to take account of the effect of two of the operator's officials having checked the OP's ticket or having been prompted to take the opportunity to do so. The permission given to pass through the gateline is of particular significance. I don't go so far as
@furlong in saying that the barrier's rejection of the ticket made the operator aware of the ticket's invalidity, as the programming of barriers may lead to rejection of tickets that are valid. The barrier's rejection does, however, put the operator on enquiry as to the ticket's validity: that, surely, is the whole purpose of using a barrier to check tickets. If the operator's official then allows the passenger to pass the barrier notwithstanding its rejection of the ticket the effect must be to reassure the passenger that he is entitled to travel. Even if this does not amount to the granting of permission to travel it is bound to lull the passenger into a false sense of security that his ticket is valid for travel and he is thereby deprived of his last opportunity before boarding the train to correct the invalidity of his ticket by amendment (
@Skiddaw's case above) or purchase of a replacement. I would argue that the official's grant of permission to pass through the barrier after it had initially rejected the ticket amounts to a representation on behalf of the operator that the passenger's ticket is being treated as valid for travel. Relying on that representation the passenger then acts to his detriment by boarding the train when not in possession of a valid ticket. This seems to me to be classic case where it would be unconscionable for an operator to enrich itself by charging the passenger a penalty fare after such passenger had relied to his detriment upon the assurance given on behalf of the selfsame operator that his ticket was being treated as valid for travel by the grant of permission to pass through the barrier – an assurance, moreover, that was reinforced by the further check of his ticket that was made en route with no objection to its validity being raised. I suggest that this reasoning might be deployed as an additional ground of appeal under Regulation 16(3)(d) on the basis that it supplies a compelling reason why, in the particular circumstances of the case, the appellant should not be liable to pay the penalty fare.