Were you involved in the design and development of that system?
Without any prior involvement in the design or development of that system you talk of, you were asked to jump in at 3am in the morning to fix a major issue on a production environment at the eleventh hour?.....because of your extreme experience?
And then you took an “educated guess” as to what the problem could be ......and thats exactly what it turned out to be?
And then you say that you could have done a small “fix” but that would have produced inaccurate id cards. You dont have a separate test team who can easily figure out you just did a kludge?
And now you want me to explain the design problem?
I have worked with all kinds of people for a long time in the industry. I maybe lacking in a lot of things but I am not lacking in figuring out when someone is bullshiting me.