Yup. This is getting to the difference between 'lying' and 'bullshit' in persuasive rhetoric. It really is a fascinating topic.

Lies are crafted. It is manipulation with deliberate untruth - statements knowingly contrary to reality are made to convince someone of a claim. Lies are usually carefully worded, so as to withstand scrutiny. Successful liars are usually very intelligent. They have to be, since it requires careful attention to detail and good memory. A carefully crafted web of lies can be a tough knot to untangle for determined opponents. Liars usually have big plans and wide vision.

Bullshit, on the either hand, is simply emitted. It's truth value is irrelevant. What matters is how it makes us feel. It is made up on the spot, for the temporary relief of discomfort. It falls apart with the most minuscule scrutiny, but by then, it usually doesn't matter- it's done its job by exerting its emotional effect. Bullshiters don't need any of the brain power that liars do. Bullshit is created impulsively, in the moment.

Omnivore excuses fall under the category of bullshit.