McConnell's spacing out twice in public like he did is evidence. Who says it has to be a lab test? Not to mention he would have had a thorough workup after his first observed petit mal seizure so that doc is lying like the way Ronnie Jackson lies.
Nothing mimics those symptoms that I'm aware of.
You are correct of course that it
is evidence - but is it
sufficient evidence?
A TIA (transient ischaemic attack, aka mini stroke) is also in play.
And some, whatever, third and as of yet unknown cause.
I do agree that it "looks like" a seizure an aweful lot and have that as the most likely hpothesis.
But "looks like" does not equal "is". I'd require at least one further differential diagnostic test that either confirms seizure or rules out TIA.
This is important, because while absence seizures do not disqualify him from office, as a person can otherwise function pretty well with such seizures for a long time without significant deterioration of mental capacity, TIAs do affect the brain's functioning: With every TIA, something is potentially lost. A series of TIAs (which can be silent, symptom-less) can lead to multi-infarct dementia, which
does disqualify a person from jobs that require sharp cognitive functions.
Clearly, further diagnosis ought to have been carried out on McConnell following these events - for starters, his own account of how he experiences the events helps in differentiating TIAs and seizures. Imaging methods, measuring blood flow, lab testing of blood sample for signs or risk factors of TIA should be done.
We don't know if any of such diagnostics have been done or which, nor what the results were.
Consequently, I'd expect McDonnell to be on medication already to prevent further incidents - and if we knew the medication, we would more or less know the diagnosis. But we don't know.