Status > System Logs > DHCP reporting

[hda]

Funny, I observe only 2 leases on this system :), other hosts are static outside of the pool(s).
Latest Base System 2.3.1.a.20160426.1538

[cmb]

You mean the "wrote 3 leases to lease file" part? Probably has a third that dates back prior to your log. Check /var/dhcpd/var/db/dhcpd.leases