What if Arnav read the heading of the other papers (the ones Khushi wanted signed) though Khushi gave it to him saying that Akash sent those papers for getting his sign? And that's why he purposely signed in a different manner for only those papers and those were the papers that were showed to us? So even if Shyam has got the signed papers, he can't benefit from them because he would need the original sign and thinking that he's got the signed papers he'll end up revealing everything to Arnav...