New tires and now brake pad light is on. (pads are good)

[500-SEC]

Just had new tires installed today on my 500SEC and just as soon as I left the shop the brake pad indicator came on. I read the manual and it said that the light only tells you if the front pads are low. I checked the pads today while it was at the shop... The fronts are at least 50-60% left, while the rears are needing replaced soon, maybe 15-20% is left back there.

Going down the road the light isn't on, but at a stop it will flicker for a second and then go to a solid amber color. My question is... Do you think the shop messed something up while installing the tires? Can the light be triggered by the back pads? Thank you in advance.