There is definitely a failure to consider on vague locus, and importantly it's a complete failure to consider so it meets the threshold of Halton Borough Council, R (On the Application Of) v Road User Charging Adjudicators [2023] EWHC 303 (Admin).
As above, your choice is fundamentally to either take the discount, or pursue an appeal.
What I will add is that Redbridge seems to be struggling to put evidence packs together at the moment, it might be that they're short staffed. If there's no evidence pack from the council, you win by default as there would be no evidence of any contravention.
Let us know what you decide to do.