Event Triggered When Not Expected When Deleting Protected Cell Data

I have a relatively complex excel VBA solution which has a top level spreadsheet containing a dashboard of stats (test statuses within projects).

There are various reporting options available which open other spreadsheets to collect data and present it within the top level spreadsheet - these are closed once the data has been copied.

For example, I select an option to show me all the issues relating to tests for a particular team and the solution opens a series of spreadsheets and copies the issues into the summary spreadsheet.

The problem is that the report has the option to double-click a row, which essentially opens the corresponding Excel file and focuses on the relevant row containing the issue.

This works fine but I've added protection to the report to prevent users editing the data here (they should double-click to open the underlying file and edit there).

The report is a protected sheet and locked/unlocked cells can be selected - in fact, they need to be to allow the double-click event.

If I put my cursor in a cell and click Delete then pass over the warning that the sheet is protected then select Enter, Excel raises error "1004: Select method of Range Class failed".I understand that use of worksheet select is not a good idea but what concerns me is that the event which occurred prior to the double-click (the one which collected the data for the report) is running when it shouldn't be so.

Why would the earlier event be triggering and why doesn't it hit my breakpoint placed in the related code block even though that must be running?