LC UNDERDRAWN DISCREPANCY VALID OR NOT

[Charonxi]

COMMODITIES L/C:
INFO AS FOLLOWS:
LC AMOUNT: USD100,000
PARTIAL SHIPMENT: NOT ALLOWED
TOLERANCE:+/-10%
PART A (FIRST PAYMENT FOR 80%INVOICE VALUE):
PART B(BALANCE PAYMENT): THIS PART ALLOWS PRICE ADJUSTMENT BASED ON REPORT OF ANALYSIS
.
FIRTST PRESENTATION(BILL ARRIVAL 1)
INVOICE VALUE:USD100,000
WE MADE A PAYMENT FOR 80%INVOICE VALUE(ETC USD80,000) UNDER COMPLIED PRESENTATION
.
NOW SECOND PRESENTATION(BILL ARRIVAL 2)
INVOICE VALUE CHANGED DUE TO PRICE ADJUSTMENT: USD85,000
SO THE BALANCE PAYMENT IS USD5,000=USD85,000(CHANGED INVOICE VALUE)-USD80,000(FIRST PAYMENT)
.
NOW THE QUESTION IS:
IN THE SECOND PRESENTATION, DISCREPANCY ABOUT 'LC UNDERDRAWN' IS VALID OR NOT?