NATS immobiliser light staying on Almera 2001?

Bit of a long description this, so bear with me!

Went to the car the other day and unlocked using a generic plipper (not the original, but it came with the car when I bought it 12 months ago and has worked perfectly so far). Got into the seat and noticed my battery light, engine management light and NATS light were permanently on. Engine would turn over at a good rate, but not start.

Disconnected the earth on battery and left overnight. Next morning reconnected and now the NATS light flashes 6 times when key turned to "on". (Fault/malfunction). Tried resetting the engine with the "turn to on, turn to lock" etc, but nothing worked.

Checked the battery - wire from earth catching on plastic moulding, repositioned so clear, now everything is fine SO FAR. Started first time this morning.

Is this a glitch or "hiccup" which has now been righted, or should I bob it down to Nissan for them to check? There isn't an alarm on the car, just the immobiliser.

Thanks so so much for reading - bonus points if you understood the situation lol!