Looks like it was a net message spam issue, I cannot replicate it from manually doing this - however maybe there was a rare chance the server lagged as you were spamming it? (I also dont know why you would spam it in the first place when there's a cf limit); I'll give you the benefit of the doubt and remove the ban but if it happens again its definitely no coincidence.
The Bug You're Experiencing: Using the grappler (weapon_grapplehook) will now take fall damage as before the recent changes it didn't.
Can you reproduce the bug, if so, how?: While using the grappler, grapple yourself up to the ceiling and release. When you hit the ground you commit go die.
Examples of the bug (images, videos): Yes