Blood agar n pipette

As the cultures (Cl. difficile) show some strange result, we redo what we did yesterday. We also make some more sheep blood agar. Basically just adding a certain amount of sheep blood into autoclaved agar and pour into petri-dishes. What really surprised me is that all pipetmans were never released after used. After the work I tried to release them and found some of which seem to had been under the condition of reform fatigue for a long time. I might be wrong but as far as I know, all pipetemans must be released after using. I personally reckon any equipments require maintainance; no matter it's gadget, computer, or even laboratory things. After all, in this case, a pipetman to a reseacher is like a firearm to a soldier. I'm also wondering if the O-rings, seals and pistons have rusted or been damaged...