I'm not quite sure if I'm even answering what you're asking Paul, but I did a little research and came up with a court case that involved dropsies:
PEOPLE of the State of New York, Plaintiff,
v.
James McMURTY, Defendant.
Criminal Court of the City of New York, New York County.
Sept. 3, 1970.
Defendant charged with narcotics violation moved to suppress narcotics which policeman alleged defendant had dropped but which defendant claimed had been taken from his person in illegal search. The Criminal Court of the City of New York, Irving Younger, J., held that 'dropsy testimony,' consisting of testimony of arresting policy officer that suspect dropped packet of narcotic drugs to the ground should be scrutinized with especial caution. The court held, however, that where arresting officer testified that defendant had dropped plastic container containing narcotics and defendant testified that he had not dropped the narcotics and there was no independent contradiction of policeman or independent corroboration of defendant, motion to suppress would be denied.
Motion denied.
