heres the way i see it. to go out of your way to talk to the opposite gender can be wrong. but here they just met! he’s sitting there changing a tire…what are they supposed to do? just ignore each other? picture for example youre at a friends house, and they have a sibling your age or around your age…are you supposed ignore any attempt at converstaion? thats just plain rude…the circumstances are such that its simply polite. as for the call, why not? a person gives you a gift, the polite thing is to call up and thank them same gender or not.
we get so caught up in the avoiance of the opposite gender that we lose sight of basic decency. true to arbitrarily just walk up to someone of the opposite gender and strike up a conversation may be assur…but if youre in a situation where ignoring each other just makes it akward for the both of you…there is no reason not to talk…its just being polite. another example, is people who go to coed colleges. while they should try to minimize interaction with the opposite gender, its simply unavoidable! to ignore them would simply be rude.
i think the bachur was just being polite, and that the shadchan just messed up a perfect opportunity