by Richard Oelmann.
Time remaining on the tutor view shows the time remaining/overdue between the due date and the current time/date.
The red highlighted text for the student shows the overdue time when the last modification was made to that student submission. Although that student is showing No submission, they are also showing a 'Last Modified date' (Tuesday, 5 April 2016 1:44 AM) and so there must have been some activity in the submission by that student (you can check exactly what in the logs). So the overdue highlighted time is the measure of that Last Modified time past the due date&time.
2 completely different things, therefore 2 completely different figures and not a weird issue at all.