"The former FBI director with an ego almost the size of Donald Trump’s"

That's an unfair exaggeration. 
Comey testified for many hours a couple of months ago and came across as thoughtful, clear-headed and very knowledgeable about roles & mandates & internal processes.

He stands very tall (6' 8" apparently) and sits erect & square-shouldered but I detected no hint of ego during those hours, nor during his various media interviews. Meanwhile, Trump is the epitome of ego: boastful, claiming expertise when he has none, taking credit on spurious grounds, assuming that he can hustle & grope women with impunity, exaggerating and outright lying, etc.

No comparison....