Question about the ending (spoilers)

After Konga dies, his body returns to that of a baby chimp. So was it all just a voodoo spell, and not actual science? I know scientifically it would be impossible for anything to increase in size that quickly, as Dr. Decker should have known. But he kept going on about how it was going to revolutionize science.

Other than that minor point, the plot seemed plausible.