Review Java Code and Find Errors

This dispatcher queues outgoing commands to a field device and is meant to retry anything that fails to send, tracking the failure rate for an operator dashboard.

import java.util.ArrayList;
import java.util.List;

public class TelemetryDispatcher {

    private List<String> pendingCommands = new ArrayList<>();
    private int retryCount = 0;

    public void enqueue(String command) {
        pendingCommands.add(command);
    }

    public void dispatchAll() {
        for (String command : pendingCommands) {
            boolean sent = sendToDevice(command);
            if (!sent) {
                retryCount++;
                pendingCommands.remove(command);
            }
        }
    }

    public boolean sendToDevice(String command) {
        if (command.length() > 256) {
            return false;
        }
        System.out.println("Sending: " + command);
        return true;
    }

    public double getFailureRate() {
        return retryCount / pendingCommands.size();
    }
}

Review this Java code and find every error in it, including anything that would crash at runtime and anything that silently produces a wrong number. Explain each one and how you would fix it.