Existence of OG Roles module causes fatal error

I installed OG User Roles without having first uninstalled OG Roles which resulted in this error:

Fatal error: Cannot redeclare _user_roles() (previously declared in E:\drupal\sites\all\modules\og_roles\og_roles.module:199) in E:\drupal\sites\all\modules\og_user_roles\og_user_roles.module on line 403

No, I did not first read the README.txt that warned of this error (shame on me).

However, the installation of a module should never render the site completely inaccessible - even if the behavior is clearly documented. Instead, I would think that relevant scripts should check for the existence of modules known to be incompatible and handle that situation gracefully.

At least for now, please provide a clear warning in the description field in og_user_roles.info until this issue can be handled better. It currently says "NOT same as OG Roles" which is hardly a warning.