Cylinder Head Question

Ok so my mechanic told me that my head needed to be rebuilt. I am looking for some opinions. What he did to try and convince me was showed from under the valve cover that several of the exhaust side lifters would rock back and forth when he pushed on them. I see no blue smoke nor do I have any smoking issues. I am not loosing oil that I can tell. Does his "test" truely mean it needs a rebuild?