The way the K2 SharePoint event integration works is that an event, such as the creation of a list item, can kick off a workflow but it is done asynchronously due to the way the SharePoint eventing system is architected.  A task can be assigned to the user which points them to a page where they can take the action of setting a list item value but the user will need to open the worklist item from their task list.  We can not pop up a redirect page upon creation of an item in SharePoint.

In K2 blackpearl you can build your own ASP.net pages which could surface a smartobject for the sharepoint list which would allow the user to create a list item from your custom page and kick off the workflow at the same time.  In the K2 API you can specify to start a process synchronously which could then actually start the process and redirect the user to the first task without having to go to a worklist.  This custom ASP.net page could also be surfaced in SharePoint using the page viewer web part to achive an integrated experience.