It does not, assuming he is not on a porch, or in fact a monkey.
Many nouns, compound, part of a phrase, or otherwise, contain some element based in fact. That doesnt make them objectve factual statements.
I don't care about hypothetical alien space robots.
It need not. My white ass is referred to as the n-word on the regular, despite not being A) black (arguably), or B) intended to insult.
No, i just use allegation in its normal sense of an accusation, normally indicating unproven wrongdoing. Whether someone is called tall does not meet that bar, and conflating this ◊◊◊◊ is not productive.
The employer almost certainly should, if she were firing you for no other reason than someone else voicing their opinion of you. The one who called you a bigot should face no repercussions at all. They had no power over you or your destiny. That was your employer's choice, and a poor one.
And you are putting a lot of effort into grossly exaggerating what an allegation is. If you broaden it to any statement of fact or opinion that hasnt met some random evidentiary standard, ok, but it has no import anymore. Certainly not enough to raise it to the level of criminality, which you subtlety restrict the meaning to in the latter part of your argument. Calling you 'tall' ain't going to land me in the pokey, no matter your height.