This is the license: http://www.publicsource.apple.com/license/apsl/

In the documentation it notes that it lifts liability for the original code only, not modifications. So am I able to add a "cannot be held liable" statement for the modifications I've made? Also am I able to license the modifications I have made? Or should I leave that out.

Yeh, but that's why I was wondering if I can add my own no warranty clause (or possibly even a full license, pretty sure I can't do that though) for the modifications I made.

Like here's an example of what I put in files of theirs that I've used and modified.

Link to original code
Who modified it and when
The modifications that took place
The APSL license header as found in the original code
The code

I think that meets all their requirements for modified code. But I'm not sure if I should just leave it like that, or if there's anything else I should do or not (e.g. should I add my own "cannot be held liable" notice?). Note that the rest of the project (where it's only my own code) is released under FreeBSD style license.