HTML in log will not render

I'm using the following code in an OnLogError event handler to turn an error stemming from a File checkpoint into a warning:

  if (LogParams.MessageText.includes('The file checkpoint')) {
    Log.Warning(LogParams.MessageText, LogParams.AdditionalText, LogParams.Priority);
    LogParams.Locked = true;
  } else {
    Runner.Stop(true);
  }

It seems to me this should take the values of the original Log.Error and insert them 1:1 into the warning. However, the HTML is not rendered:

Now one thing I've noticed is that, whereas in the TC desktop-application the HTML shows with its closing </body> and </html> tags, they are not printed in the TestExecute details. Could this be a hint as to the solution; would it render when I append these tags to the LogParams.AdditionalText ?