One thing more Ranee, here the wife committed suicide. Dowry Demand definition says that the act of cruelty can only be considered u/s 498a if (c the below judgment from SC) and the one you have quoted has already been overruled by the Apex SC. But still i feel if it is a real act of illicit relation, he should be convicted for cruelty (though we do not have any other section for cruelty) but not for dowry demand.........
Bhajan Lal Bhatia & ors. Vs. Sarita Neelam
2005 Vol I HLR 59. Where evidence on record neither
disclosed that there was cruelty on part of the
accused which was of such a nature as was likely to
drive victim to commit suicide or cause grave injury
or danger to her life or limb or mental or physical
health nor showed that she was harassed by accused
with regard to any demand for additional dowry,
section 498-A could not be attracted in such
circumstances in Bomma Ilaiach Vs. State of U.P. ,
2003 Cri LJ 2439 (AP).