Can a plugin manually raise another plugin's Event?
I've built a plugin which uses it's own events before, I guess the way to do it would be the same for separate plugins, however this is untested for your use case.

This should go in your plugin service

// Import the event from the other plugin
Craft::import('plugins.otherPluginHandle.events.OtherPluginEvent');

/Initialise the plugins event and pass whatever is required to it.
$event = new OtherPluginEvent($this, array('request' =&gt; $request));

// Raise it.
$this-&gt;raiseEvent('OtherPluginEvent', $event);


Again I haven't tried this from the context of calling another plugins event, but that is what I do from a plugins own event...