I think this question is a particularly stupid one.... not all women know it and now all men know it. Those interested in football will, and as for the Andy Gray situation.. if it was a male linesman nobody would of questioned the decision.. I don't feel it is up to Sky to sack him, they should ask the female linesman how she feels about the situation, i would imagine she is mature enough to ignore such petty remarks. At the end of the day refs linesmen and managers all struggle with the off side rule.. when a player is deemed off side you will usually see the manager of the opposite team kicking off..
I just think the whole situation is ridiculous... if she didnt know the offside rule she wouldnt of been hired as a premier league lineswoman.... so she obviously does, end of.. it was a right decision to make..