I've never used the module, but a quick look into Net::IRC::Event shows that kick is the event that would be called:

kick 

The "kick" event is triggered upon receipt of a KICK message, which me
+ans that someone on a channel with the client (or possibly the client
+ itself!) has been forcibly ejected.
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Thus, your code should look something like:

$conn->add_global_hander('kick', \&on_kick);

sub on_kick {
    my ($self, $event) = @_;
    my $who = $event->nick;
    # $who is the person who was kicked.
}
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Update:

Note: you can use Data::Dumper to see what the event structure looks like:

use Data::Dumper;

# ...

sub on_kick {
    my ($self, $event) = @_;
    print Dumper($event);
}
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HTH.