It was an FTP error. That line of code kept on getting corrupted. Initially I uploaded using Windows Explorer (lazy/ silly, I know). I then used SmartFTP, on ‘auto’ mode (which would’ve been ASCII for PHP files) and it kept corrupting that file. I then put it on Binary mode and it kept corrupting it.
Eventually, I opened the remote file in HTML-Kit, the local file in WordPad and replace the contents of the remote version with the local one, saved it and all ok.
However, I’m now a little nervous — which other files might have got corrupted without me knowing about it??