The following is an excerpt from page 8 of the Warhammer Annual 2002 release with an expanded explanation by Gav Thorpe regarding the Skirmishers and overrunning.

In a recent battle report, Alessio had a lone character which made an overrun and, rather than simply continuing straight on, went off in a different direction. He has subsequently realised the error of his ways and under suitable physical inducement has proffered an apology for confusing people. Like everyone else, skirmishing units and lone characters overrun straight ahead; the fact that they can see 360° around themselves makes no difference to this.