To throw in the towel means to give up, quit or abandon something, but in this context the person is wasn't ready to persevere or continue trying but rather was trying to give up.
Context: "That made things a lot more difficult, but it didn't mean he was ready to persevere and continue trying." Claim: "That complicated matters greatly, but it didn't mean he was ready to throw in the towel."
Considering the context, is the claim true, false, or unknown?