It don't matter if its downloaded through PSN or installed by Package files.
Once you choose to play online, whether using a spoofer, PSN PATCH by kokotonix etc, it's all at your own risk on why Sony might choose to ban. As said, they have banned people on OFW for using mods etc.
And yet you may not get banned. Just saying anything can and will happen when it comes to Sony.
I doubt it would be a console ban, but again who knows
Install the DLC, then reboot PS3 and run PSN Patch if you must go online.
For those who insist on playing online, there are guidelines to try and follow to try and help you not getting banned. But nothing is fool-proof.