Actually, this patient had gotten fluid earlier so depending upon an in-depth lung assessment (which the only information given here was "tight") as well as a cardiac assessment, Lasix definitely may have been indicated. And some form of diuretic therapy IS indicated in heart failure management, especially exacerbation which might be caused by right heart failure. Diuretic therapy is driven by kidney function, better to be a bit dry than wet.
And re: orthopnea, that was not listed when the symptoms were discussed, what was stated was " he had been complaining about not getting much sleep". As this pt was post-op for CABG, that is not an uncommon complaint.
Your post jumped to some conclusions that weren't supported by information presented by OP. And as this patient went into an acute situation rather quickly, NTG and ACE inhibitors wouldn't have been indicated, IV inotropes would have been indicated as well as the possible use of Milrinone if the patient stabilized, which unfortunately didn't happen. IMHO the OP was looking for support regarding a situation which deteriorated rather rapidly...not a lecture on presumed heart failure management.