Spot the validation gap

You enabled API Gateway request validation on your POST /transfers endpoint. The validator requires an Authorization header, requires an accountId query parameter, and checks that the JSON body matches a model with a numeric amount field. A request arrives that satisfies all of those rules: it has the header, the query parameter, and a well-formed body with amount set to 5000. However, the transferring account only has a balance of 100, so the transfer should not be allowed.

What will API Gateway request validation do with this request?