Possibly so, if there is water in the lungs. But by pathology, we might be able to determine whether or not he was dead... before he went into the river.
Hugsanlega, ef ūađ er vatn í lungunum en meinafræđin gæti varpađ ljķsi á ūađ hvort hann var dáinn áđur en hann lenti í ánni.