Superloop

Hi

I was driving into work this morning and had to step on the brakes sharply. ABS/EBD kicked in and the car pulled sharply to left and brakes felt like they we're doing nothing. The brakes were fine unless you pressed really hard and then again go crappy and pull to left. Then as if by magic all went well again and sharp test braking went back to pulling up nice and straight.

The car is an 04 WRX ppp it was wet and i'm wondering if there was maybe diesel on one side of the road or something and once that had gone off the tyres it sorted itself??

Anyone got any ideas????