I don't know what you mean by "hold up in court". This seems to be an instance of software engineers making sweeping prognostications about legal matters.

"Hold up in court" as in was it duly executed and filed by a certain date, regardless of the time and extra management required for the bank's performance? Yes, why not.

"Hold up in court" against someone claiming it was an unauthorized transfer? Even without the bug, that can be contested in many straightforward ways!

But unless there is a specific legal claim that hinges on the bug being significant, it's pretty irrelevant "in court". I knew about this precisely because the transfer failed to go through due to redundancy - one digit in account numbers is generally a check digit, plus account titles and whatnot.

In general you can always challenge the validity of scanned documents, regardless of known software bugs or not! Just like you can always challenge that a paper document is a forgery. You need a specific argument and some evidence though!