Maybe just maybe we have a case of different ways of uptake in the body for the different forms.
But I highly doubt it but would need to read up to be sure.
And then there is also the point that the time before converting makes a difference in the way the peak concentration is reached. But I also wonder if that makes a huge difference in this case.
Honestly I think someone just put it together without really having a good reason but I may get proved wrong.