My dumpster diving days are far behind me, but that attitude used to be called "freegan".

For me, I wouldn't criticize anyone who chose to eat animal flesh sourced in this manner - no one in the capitalist supply chain is going to make any money off you, you're not increasing demand for animal flesh, eating that flesh does no harm to any living animal and makes it no more or less likely that more animals will be killed.

At the same time, the personal is political, and part of that is living your values in a way that is not only consistent but appears consistent to others. Publicly eating like a vegan, and sharing how your diet reflects your system of ethics, normalizes veganism and encourages people to respect and consider your point of view. Every time you, as a vegan, share a meal with others, you are also sharing your values, even if you unobtrusively choose a vegan meal option and don't say a word about other people's choices.

But if you call yourself a vegan, and then you eat meat, or wear leather, or otherwise consume animal products, it taints you with perceived hypocrisy, discredits your words and actions, and makes other vegans look bad by association.

Also, it just feels icky.

OP, I would ask, are you part of a collective? Are you in contact with other dumpster divers you could share or trade food with? Because I hate the waste involved, too, and though I wouldn't eat the animal flesh myself I would be willing to give it to someone whose ethics permit it.