This is probably a stupid question, but does anyone have an obvious explanation for me as to why my ABS and ASR lights would randomly come on whilst driving?

Lights came on tonight, parked up for a couple hrs, when I started her up again, just the ABS light, then that went after a minute or so, then a minute or so later, both back all the way home.

I know I should probably Vagcom it, but anything spring to mind? The only change lately is 4 new Proxes, an MOT and a service. Thanks in advance.

Bumped a wheel speed sensor whilst having the new tyres fitted?