Visual Fortran /check:bounds

Hello,
I have been looking at the behavior of the check:bounds compiler option, and in particular I read through this forum thread. I had a memory corruption in a program I'm writing (which I fixed now) that I think should have been caught by the run-time check. I adapted an example from the forum thread to demonstrate the behavior:

      program ex

        implicit none

        call modify(5)

      contains

        subroutine modify(n)

          implicit none

          integer :: n
          real(kind=8) :: a(3)

          print*, a(1:n)

          CALL modify2(a(1:n),n)

          a(1:n) = 10.5D0

        end subroutine modify

        subroutine modify2(a,n)

          implicit none
          integer :: n
          real(kind=8)  :: a(n)

          a(1:n) = 10.0
          print*, a(1:n)

        end subroutine

      end

The behavior I am questioning is: Visual fortran gives me the error "Subscript #1 of the array A has value 4 which is greater than the upper bound of 3" at line 20. I agree that indeed, I go out of bounds at that moment. I understand why I do not get the error at line 30, since I think Fortran allows to pass only parts of arrays and then access the subsequent elements simply because they are contiguous in memory.
However, I do not understand why I do not get a runtime error at line 18: I am explicitely asking Fortran to pass an array of size n=5, when a is only size 3. Should that not result in a warning? Or what is the use of allowing such behavior?

Thanks in advance!
Etienne Pellegrini

EDIT: I am running Intel Parallel Studio XE 2016 Composer, Version 16.0.0046.12