mbsharp

Your code to check the PHP level did work correctly.
I changed the line in ewz-base.php so the parse error didn’t occur. But the activation then reported the requirement for PHP5.4
The problem was that I had asked the hosting system to use PHP5.4 (actually 5.5), but my original WordPress installation had inserted (in my local installation) an environment setting for 5.3 which I didn’t know about.

Once I had changed the environment setting, and put ewz-base.php back to its release state, the activation worked fine.

I wonder how many others may have a setting hidden in an .htaccess file that they don’t know about.

I fixed it.
I changed the code line as suggested and activation then failed claiming I was not up to PHP level 5.4
Although I had requested a change to PHP5.5 via my hosting service console, my WP folder has an .htaccess file and that had an environment setting for PHP 53.
I reverted the hosting console to 5.4, and edited the .htaccess file to 54, and the plugin activated with the original code.