I do agree to what your're saying, but from java coding side, the following line will always create exception because you're assigning a reference of Map request Object to BigDecimal object, when this line is executing catch block on line 727 and showing printstack trace and getting continue there.
BigDecimal amount = (BigDecimal) request.get("x_Amount");
I've debug this issue on my local for Apache OFbiz 13.07.01 and find that when getXAmount(request) method is getting called in processAuthTransResult, processCaptureTransResult etc.., but when I put suggested patch then code is executing fine and there is no catch block is executing. I've seen same problem while executing Void, Refund & Authorization transactions.
I understand its not big issue, but logs showing error related to above mentioned code for most of transactions. Could you please let me know your decision on this issue? Many Thanks.