In my CC folder I have a folder shared with a colleague. When I delete items from the shared folder, they immediately re-sync to my PC.
1) From Windows Explorer, I delete the files located in /Creative Cloud Flies/Client_A/Project_1/Topic_X
2) They immediately start syncing back to my computer.
I spent 30 minutes on the phone with a CS rep. She simply couldn't understand that deleting them from my computer, then deleting from the archive, then deleting from my computer again is not an efficient workflow.
Its hard to say for sure without more info, but If your colleague collaborated a folder with you, they define rights when setting it up - (Can Edit) or (Can View). If they had set it to (Can View) and you were deleting the file through Explorer I could see the Creative Cloud app recreating and resyncing it like you described. I'm not sure if that is what was happening or not, just a guess based off of your description.
Here are some collaboration related resources which may or may not be helpful/related: