Undefined offset error, but offset is not undefined

Question

I'm getting a Notice: Undefined offset: 0 error in my code, however I can print_r the element I am trying to get and its clearly defined.

function get_members($entries_found) {
   $members = $entries_found[0]['member'];
   ...
}

If I print_r($members) I get the expected output, however I'm still getting the Notice.

Any clues?