you really think that entire large meeting just randomly happened to happen next to the tree he picked to leave a walkie at? I honestly thought it was inside a cave tbh.in ch.9 he left one next to a tree, so it's more probable that the bandits were talking near the tree, remember that they were gonna talk with the bandits infiltrated in the village if they were gonna attack in the end, so that's what was probably happening when the MC started to hear in the walkie talkie.