Exterior lights alternate flashing

I have a friend who bought a Town and Country about a month ago, used 2002 or 2003 I believe, after about a week, the battery died and so we replaced it. Now its been about 3 weeks since then, and he called me telling me that the headlights and driving lights are flashing alternately. I thought it sounded like the panic button was hit, but they tried pusshing all the buttons on the key fob and nothing changed. The doors locked and unlocked when the buttins were pushed, but the lights continued. So they drive it to my house with the lights flashing. Once they got here, I too proceeded to push buttons and nothing worked. I looked under the hood and heard a relay ticking in the fuse and relay box. So I disconnected the battery and checked the relay. It was fine, put it all back together and connected the battery and it stopped flashing the lights. This was good, bt we still would like to know what could have caused this in the first place. Is there a trick to the panic button and that was the reason it did it. If anyone can give suggestions for the next time!

Thanks

Jeff Cates