DHT11 / clearWatch error weird behavior

You should set the pin mode in the connect function to pinMode(ht.pin, 'input_pullup');, to avoid random signals to be received.

And you could replace a code of code as follows, mainly for better comments, from

...
  digitalWrite(ht.pin, 0);
  pinMode(ht.pin,"output"); // force pin state to output
  // raise pulse after 1ms
  setTimeout(function() { pinMode(ht.pin, 'input_pullup'); pinMode(ht.pin); }, 20);
  // stop looking after 50ms
...

to

...
 //pull signal to ground for 20 ms to request data from DHT11
  pinMode(ht.pin,"output");
  digitalWrite(ht.pin, 0);
  setTimeout(function() { pinMode(ht.pin, 'input_pullup'); }, 20);

  //parse the received data after 50ms
...