The first think that occurred to me is that the app could list the transactions this would cause and present that list for confirmation, along with a total and how much of the whole it was.

It would make the error much easier to spot.

OTOH, the people approving may not have the right to see values, just the process part they are involved in.

This and the aerospace mention reminded me of John Glenn: "two million parts, all built by the lowest bidder".