Why Does Sidebar Open Internet Explorer Instead of My Default Browser?

When Cirrus Insight needs to open an internet browser, it does so by calling Outlook.  Any action that opens a browser session does so in Internet Explorer despite the default browser being set to Chrome in both Outlook and Windows, because the Microsoft infrastructure opens Internet Explorer (this is not a user setting).  This is also why certain security settings in Internet Explorer, like "Delete Browsing History on Exit" and safe sites can have impacts on the sidebar behavior.