Event Handlers in C# - Alternative approach

Question

Can anyone answer why in the Microsoft Documentation for Collection (T) the following line is defined

EventHandler<DinosaursChangedEventArgs> temp = Changed;

What's it's advantage over directly referring to Changed instead? thanks!

public class Dinosaurs : Collection<string>
 {
    public event EventHandler<DinosaursChangedEventArgs> Changed;

    protected override void InsertItem(int index, string newItem)
     {
    base.InsertItem(index, newItem);

    EventHandler<DinosaursChangedEventArgs> temp = Changed;
    if (temp != null)
    {
        temp(this, new DinosaursChangedEventArgs(
            ChangeType.Added, newItem, null));
    }
}

I can't seem to figure out why the below approach isn't used ?

public class Dinosaurs : Collection<string>
 {
    public event EventHandler<DinosaursChangedEventArgs> Changed;

    protected override void InsertItem(int index, string newItem)
     {
    base.InsertItem(index, newItem);

    if (Changed != null)
    {
        Changed(this, new DinosaursChangedEventArgs(
            ChangeType.Added, newItem, null));
    }
}