[spokeshave]

But McCain’s emergency surgery on his eye was more than convenient, followed by his brain cancer diagnosis.

He had eye surgery followed by chemotherapy for brain tumor

So why is he wearing a "Hillary" boot...?

[COUNTrecount]

Reported as a complication from chemo.

[EVO X]

So why is he wearing a "Hillary" boot...?

There are drugs that can cause tendons to rupture such as Cipro. I am guessing this one possibility..

[Qiviut]

So why is he wearing a “Hillary” boot...?

+++++++++++++++++++++++++++++++++++++++++++++++++++

A cancer doctor (so he claimed) on Reddit said he suspects the boot is to disguise/hide “foot drop”. Foot drop, sometimes called “drop foot,” is the inability to lift the front part of the foot. This causes the toes to drag along the ground while walking. Foot drop can be caused by brain or spinal disorders.

Two other comments he made - the type of tumor McCain has usually reoccurs within 6-12 months (after it’s been treated by whatever means) and that McCain appears to be losing weight.