To cry uncle means to admit defeat or plead for mercy, which is what the speaker is saying they would not do.
Context: I knew I wasn't strong enough to put up a wall against it, but I would not admit defeat or plead for mercy.
Hypothesis: I knew I wasn't strong enough to put up a wall against it, but I would not cry uncle.”

Given this context, is the hypothesis true (Yes/No/I don't know)?