Landcrusier window surround rust, common problem?

Hi

To cut a long story short, a friend of mine needed a brand new windscreen
for a Toyota Landcruiser 1991/1992, on fitting the company left a scratch
all around the windscreen rubber when removing the old rubber surround
causing it to rust over a period of time. On writting to this company they
said it is a common problem for Landcruisers pre 92 or 93 to rust around the
rubber surround as they claim a process in manufacturing of the Landcruiser
causes this.

I need to know if the company involved statement is true that this area is
partucularly prone to rusting, would anyone agree, or would anyone disagree
in saying that it was the window fitting companies fault.