A lot of confusion is caused when viewing the Note and Timeline control for activities, as it always show the Modified By and Modified On fields.

We usually expect to see the Owner and the Created On fields of an activity. Since activities are already sorted by creation date in the timeline control, it is confusing when a record is modified recently and still it shows in a listing order that don't match the presented date.

Additionally a task can be modified by user other than the owner, so showing the modified by user gives and impression that he/she is the owner of the activity/note.

So the user experience will be much better if Created On and Owner fields are on the timeline control instead of the Modified by and Modified On fields, or give us the flexibility to control the fields that appear on the control through customising the view used by the control.