Do you have any example other than integer overflow?
It's the only difference I've ever heard referenced.
The Dart team spends enormous efforts on maintaining JS-compatibility, so much so that it rejects adding any language features that can't efficiently compile to JS.
Another example where the VM and dart2js differ is, as others linked to elsewhere in this discussion, that dart2js relies on undefined/unspecced behavior in browsers,
It's the only difference I've ever heard referenced.
The Dart team spends enormous efforts on maintaining JS-compatibility, so much so that it rejects adding any language features that can't efficiently compile to JS.