Statistically, there is a 60% chance it is a true positive and a 40% chance it is a false positive.
If the western blot is indeterminate, that means that they cannot call it a positive or a negative. However, if the indeterminate lasts for 6 months, then it is very likely a false positive (as no seroconversion has taken place).
Yes, I think that decision is good. That way if he has a low positive, then you can both get western blots, a little togetherness!