How does ISR disable further interrupts in hal_key.c?

Hi,

I am using Z-Stack Home 1.2.1 on CC2530

What am I missing? In hal_key.c the notes state:

If interrupts are used, the KeyRead() function is scheduled
       25ms after the interrupt occurs by the ISR.  This delay is used
       for key debouncing.  The ISR disables any further Key interrupt
       until KeyRead() is executed.  KeyRead() will re-enable Key
       interrupts after executing.

But in the ISR it looks like they are not disabled, nor are they re-enabled in KeyRead();

Also, it is HalKeyPoll() that is called by the OSAL task and not KeyRead().

Hal Driver API.pdf Section 6.3 also says that KeyRead() is the function called. 

I have searched the forums but can't find any information. I just wanted to make use of the 25ms debounce functionality in my app.

Thanks for your help.

Andy