I just want to bump this issue. I'm aware that Defender file scan will find my php_errorlog and notify me... so I'll check the logs and delete them just to stay on top of what might be problematic... but...
The latest scan (I don't recall a problem before Defender 1.4 update) showed the following code:
[20-Apr-2017 23:28:23 UTC] PHP Warning: md5_file(<SITE_FOLDER_OBSUCRED>/wp-admin/php_errorlog): failed to open stream: No such file or directory in <SITE_FOLDER_OBSUCRED>/wp-content/plugins/wp-defender/app/module/scan-module/component/class-wd-detect-file-change.php on line 75
... so it seems Defender throws a warning that causes the file to appear, which file it then reports! HMMM... seems to be making work for itself!