As given in https://phpunit.de/manual/current/en/installation.html#installation.phar.verification, the steps to globally install the PHAR are:
$ wget https://pha
I cannot reproduce the issue you describe:
$ wget https://phar.phpunit.de/phpunit-old.phar
--2016-04-07 09:47:35-- https://phar.phpunit.de/phpunit-old.phar
Resolving phar.phpunit.de (phar.phpunit.de)... 188.94.27.25
Connecting to phar.phpunit.de (phar.phpunit.de)|188.94.27.25|:443... connected.
HTTP request sent, awaiting response... 302 Moved Temporarily
Location: https://phar.phpunit.de/phpunit-4.8.24.phar [following]
--2016-04-07 09:47:35-- https://phar.phpunit.de/phpunit-4.8.24.phar
Reusing existing connection to phar.phpunit.de:443.
HTTP request sent, awaiting response... 200 OK
Length: 3086772 (2.9M) [application/octet-stream]
Saving to: ‘phpunit-old.phar’
phpunit-old.phar 100%[=====================================================================================================================================>] 2.94M 3.97MB/s in 0.7s
2016-04-07 09:47:36 (3.97 MB/s) - ‘phpunit-old.phar’ saved [3086772/3086772]
$ php phpunit-old.phar --version
PHPUnit 4.8.24 by Sebastian Bergmann and contributors.