Same thing happened to me. The first 4 HVs he took fine even though he was already considering a SiM school. But he was waffling so I sent him 3 more HVs thinking that would put me on his list.
He rejected the last 3 HVs and basically told me to F* off.
First time I've seen that - in the past they either reject me the first time, keep waffling, or break down and consider me.
Cut my losses and moved on, but it puzzled me.