I added /* */ comments to a code-block to temporarily disable an element, and it resulted in the indicator-lines ALSO being tilted, on the Dart-VSCode-Plugin release v3.8, and VSCode 1.41.1.

Screenshot:

I am using the SynthWave84 theme, with custom css enabled in VSCode (necessary to get the theme running), using Fira Code as Font set to size 15.

And then had a short conversation on twitter with @DanTup about it ;) https://twitter.com/DanTup/status/1222532898294763522

It happened on this code-block:

Widget _buildPanel() {
  return ExpansionPanelList(
    expansionCallback: (int index, bool isExpanded) {
      setState(
        () {
          _data[index].isExpanded = !isExpanded;
        },
      );
    },
    children: _data.map<ExpansionPanel>(
      (Item item) {
        return ExpansionPanel(
          headerBuilder: (BuildContext context, bool isExpanded) {
            /*return ListTile(
              title: Text(item.headerValue),
            );*/
            return Card(
              child: Column(
                mainAxisSize: MainAxisSize.min,
                children: <Widget>[
                  Text("asdsa"),
                ],
              ),
            );
          },
          body: ListTile(
            title: Text(item.expandedValue),
            subtitle: Text('To delete this panel, tap the trash can icon'),
            trailing: Icon(Icons.delete),
            onTap: () {
              setState(
                () {
                  _data.removeWhere((currentItem) => item == currentItem);
                },
              );
            },
          ),
          isExpanded: item.isExpanded,
        );
      },
    ).toList(),
  );
}

Would love if you could take a look at this! :)