Not a Doc, but played half a patrol medic once or twice...which means I don't know what I'm talking about.
I've seen a fair few young/fit soldiers fall over on the parade ground for locking their knees and not wiggling the toes.
As well as an increasing number of older Vets falling over on ANZAC Day down here, we try to put them in chairs with pride of place, rather than standing on parade.
I've personally seen 2 recently, one cracked his head wide open, the other died.
Merkel's 64 and looks quite unfit.
Not entirely unexpected result on occasion.
But defer to the medical professionals on what the deal was with her.