[Plugin: Exec-PHP] antispambot() parsing problem?

Hi, forgive me if this is a silly question. I’m still trying to get up to speed.

I want to use antispambot() to hide an email address on a page of my website. You can see the result under Email. The php code used to generate the source <a href="mailto:[email protected]">[email protected]</a> tag is <a href="mailto:<?php echo antispambot(the_author_meta('user_email')); ?>"><?php echo antispambot(the_author_meta('user_email')); ?></a>.

My understanding is that antispambot() should return a string with a number of randomly selected characters converted into HTML entities. Since the HTML source for this page doesn’t contain any such HTML entities, for this particular tag, I wonder if Exec-PHP is parsing the HTML entities into characters?

For reference I have included two email addresses in purely HTML entities. To demonstrate, to myself, that the source should contain HTML entities. I have also turned off visual editor and wordpresses automated correcting of HTML tags. I am using the admin role and so have the necessary capabilities.

Is this a problem with Exec-PHP? Have I done something stupid?