The code doesn't look like it should return an array.
Whats in the array?
That function will fire either:
_jrCloudS3_s3_media_confirm_is_local()
OR
_jrCore_local_media_confirm_is_local()
depending on whether the server is a cloud or not.
Those functions then both look at the if the file exists or not and if it does exist returns the file.
In the case of the cloud, the checking function is:
_jrCloudS3_s3_media_read()
The only place an 'array' looks like it could creep in is when that function returns the 'Body' part of the object as the contents:
http://docs.aws.amazon.com/aws-sdk-php/latest/class-Aws.S3.S3Client.html#_getObject
Looks like that should not be an array though.