Thankfully, help is at hand. There is a global, code-level switch you can use to totally disable the plugin/hook system so that any plugins (including broken ones) do not run.
To disable the plugin/hook system completely without accessing the Admin CP options, you need to edit includes/config.php and add the following code:
With this code in config.php, no plugins will run at all.
To re-enable the plugin system, remove the code again from config.php.