It was a silly mishap. It happens. He's a frail confused old man on a bike. It'd be remarkable if he didn't fall.
The posts you're seeing are a reaction to the non reaction by notable posters who would have run to the board to link it had this been The Don. And now YOU are going off on his BMI. It's a deflection. It's a what about of the highest order and pretty weak one at that. I don't expect much from Jim, so this is to be expected.
You however are a different story. You pride yourself on thinking you're above this stuff. And now you wanna measure waistlines. That sir, is weak sauce! But again, you're a hack like the rest of us :-)
And rest assured, since you're so big on disabusing "memes" I'm not a Trump supporter. I do however delight in how much angst he causes you.