It's hard to tell from the description without seeing the footage, but what you described does sound like one of the cheats/exploits being discussed on some social media/forums.
I'd say two things, if it happens again, capture a video immediately and post it here on your own thread and also report the player via the in-game menu, as you already did in this instance.
As for the exploit/cheating questions, EA is unlikely to comment in detail, no devs ever want to discuss exploits until fixes are deployed. Also, all players are treated as innocent until proven guilty and generally, naming and shaming is frowned upon. Having said that, such detail is typically forwarded to devs.
Your setup is a bit odd, or rather unusual, though. You said that you are using a wired LAN with Wifi/Mobile disabled, so are you using a USB-C to Ethernet adapter with an OTG cable? Is that just to provide stable connectivity, or are you also using other devices like a controller?
Just curious, as it's a lot of messing about for a mobile game heh, I guess it's a tablet rather than a phone too? Doesn't sound like you us an emulator either, anyway, lmk.
