When those overseas investors sell their properties at a loss,...

When those overseas investors sell their properties at a loss, someone else will take out a new loan to buy those properties. Making a loss is the risk you take when you invest. Meanwhile the banks business continues.

I thought the interviewer was a bit rude in the way he scoffed at pretty much all the people he interviewed. During the gfc Spain, Ireland and USA had unemployment between 10-20%. There's a number of reason why property prices crashed in each case. Just having expensive houses is not a reason for crashing.