Yep, your designer told you wrong.
The PIC's program will need to be smart enough to keep track of the pointer, otherwise if it loses power if will start logging from the beginning and overwrite the data recorded up to that point. Unless of course you want it to do that. This is not hard, most PICs have some EEPROM on board you can use to store this data. You've also got your external EEPROM. Be careful to check for low voltage before writing the EEPROM, the voltage requirements to correctly write the EEPROM can be a bit higher than what keeps the PIC running code. The Brown Out Detect may be enough to do it. Actually, simply resetting on a dead battery seems kind of dumb to me, since it'll endlessly reset and keep drawing power which can damage a rechargeable battery with a deep discharge. Detecting the low voltage and going to deep Sleep mode makes more sense.
As such, you'll now need a way to initialize the pointer, just turning it on won't do it anymore. Maybe docking can do it, maybe holding down a pointer reset button for 5 sec. Whatever floats your boat.