Laravel - Undefined offset 0 - collection.php

I'm programming a web app. The backend is a RESTFul app based in Laravel 4.

I'm having problems with a particular controller.

BedsController.php

class BedsController extends BaseController {

    /**
     * Display a listing of the resource.
     * GET /beds
     *
     * @retu Response
     */
    public function index()
    {
        //
        $user = JWTAuth::parseToken()->authenticate();
        $data = Input::get('room');
        $retoo = array();
        $hoy = date('Y-m-d');
        if( $data ){
            $d = intval( $data );
            $beds = Bed::where('room', '=', $d )->get( array('size', 'room', 'id', 'name') );

            foreach( $beds as $b ){
                $b->stay = Stay::where('bed', '=', $b->id )
                            ->where('indate', '<=', $hoy )
                            ->where('outdate', '>=', $hoy )
                            ->get( array( 'id', 'room', 'bed', 'guest', 'booking', 'indate', 'outdate' ) );

                            dd( $b->stay );
                if( isset( $b->stay->guest ) ){
                    $b->stay->huesped = Guest::find( $b->stay->guest ); 
                }else{}

                if( isset( $b->stay->booking ) ){
                    $b->stay->huesped = Booking::find( $b->stay->booking ); 
                }

                //dd( $b->stay );

                array_push( $retoo, $b );
            }
            //$room = Room::find( $d );
            //retu $room->camas()->get( 'size', 'room', 'id');
            //$beds = Bed::where('room', $data )->get();
        }else{
            $beds = Bed::where('hotel', '=', $user->hostel )->get( array('size', 'room', 'id', 'name') );   

            foreach( $beds as $b ){
                $be = $b['attributes'];
                $st = array();
                $stay = Stay::where('bed', '=', $b->id )
                            ->where('indate', '<=', $hoy )
                            ->where('outdate', '>=', $hoy )
                            ->get( array( 'id', 'room', 'bed', 'guest', 'booking', 'indate', 'outdate' ) );
                            //retu $stay[0];

                $st = $stay[0];
                            //dd( $stay[0] );
                if( isset( $stay[0] ) ){
                    if( $stay[0]['attributes']['guest'] > 0 ){
                        $be['huesped'] = Guest::find( $b->stay->guest );
                    }else{}

                    if( $stay[0]['attributes']['booking'] ){
                        $be['reserva'] = Booking::find( $b->stay->booking );
                    }   
                    $be['stay'] = $st;
                }
                array_push( $retoo, $be);
                $be = array();
            }

        }
        retu $retoo;

    }

So, when I make a call to mysiteapp.local/beds, I should get back a composite array with the bed's data and, if there's a reservation, or if that bed's occupied at the moment, the stay info and guest's info.

But all I get is a compiling error message sayin':

error:{type: "ErrorException", message: "Undefined offset: 0",…}
file:"/home/pablo/htdocs/pbertran/angularh/api/vendor/laravel/framework/src/Illuminate/Support/Collection.php"
line:788
message:"Undefined offset: 0"
type:"ErrorException"

Have been googling around, but couldn't find any solution. Any ideas?

Thanks in advance!