I had the exact same situation a couple of weeks ago which was giving me fits until I realized that the T4RIF amount in box 24 was coded as a transfer to an RRSP. If you make sure to enter that correctly on the T4RIF input form, it will carry through correctly to Schedule 7 as a transfer and thus not affect the contribution limit.

I don't know about your clients, but my client was a self-employed professional in his early 60s for whom his financial institution had rolled over some of his RRSP into a RRIF well before he had to do so. That forced him to make minimum withdrawals from his RRIF which would not otherwise have been offset by the pension deduction. To get around those withdrawal requirements, he just wanted to move his funds back into the RRSP where they originally came from.