With no attack, an ARP table might look like:
192.168.0.1 11-11-11-11-11-11
192.168.0.20 22-22-22-22-22-22
192.168.0.30 33-33-33-33-33-33 <--about to attack
When the attack launches, an entry in the ARP table is overwritten with the attacker's MAC.
192.168.0.1 11-11-11-11-11-11
192.168.0.20 33-33-33-33-33-33
192.168.0.30 33-33-33-33-33-33 <--attacking
So, yes, there are multiple IP entries for the one MAC.