According to Gerber you have no warranty on that knife at all, because you are not the original purchaser of it and it was not used in accordance to their instructions.
Limited Lifetime Warranty
Gerber warrants to the original consumer purchaser that this product, if used in accordance with these instructions, will be free of defects in material and workmanship for as long as he or she owns the product. At Gerber's option, defective product will be repaired, replaced or substituted with a product of equal value. To obtain warranty service, send the product, shipping paid, along with an explanation of the defect, proof of purchase and your name, address and phone number to the address below . REPAIR OR REPLACEMENT AS PROVIDED UNDER THIS WARRANTY IS THE EXCLUSIVE REMEDY UNDER THIS WARRANTY. GERBER SHALL IN NO EVENT BE LIABLE FOR ANY INCIDENTAL OR CONSEQUENTIAL DAMAGES. Some states do not allow exclusion or limitation of incidental or consequential damages, so the above exclusion may not apply to you. This warranty gives you specific legal rights and you may have other rights which vary from state to state. For product requiring a battery, the battery is not warranted.