This will only cause an error if short_open_tags is set to off, which is how it slipped through the cracks. We have since added automated tests that will attempt to parse the files with short_open_tags both off and on, which will stop this error from getting into a release in the future.
The fix will be released in 2.3.2; in the meantime everyone suffering from this problem should use Aram's fix.
Thanks Aram, I've never setup a SS site before so to find a problem in the install file didn't fill me with a lot of confidence from the get go.
Also, Thanks Sam for explaining the problem and putting it into context.
I was worried for a second there that I was going to have as much trouble as I did setting up a typo3 site!