I've stepped through the video and checked the parameters. As it stands, I have done the following:
1. I've put an EventsView control on the page
2. I've configured the control templates to point to ~/Sitefinity/ControlTemplates/Events/ContentViewSingleItem.ascx (single item) and ~/Sitefinity/ControlTemplates/Events/ContentViewContentItem.ascx.
3. I've verified that the control uses the two templates by putting in markers before and after the <sfWeb:CommentsList /> server control
4. I've set the CommentsList LayoutTemplatePath property to ~/Sitefinity/ControlTemplates/Generic_Content/CommentsList.ascx and modified the template to display some custom HTML:
The relevant part of the EventsView single item template now looks like this:
In the event page single item view I can see the ---start--- and ---end--- markers, but the control seems to ignore the LayoutTemplatePath, since it's not displaying the template, instead showing the default.
Also, the project I'm working on started as a fork of the Summer theme, if that has any impact on the matter.