Possibly poor treatment of dogs? Advice please?

Hi all - I recently had two dogs stay at my apartment for about 5 days, a two year old and 5 month old brother and sister. Both the sweetest dogs in the world. I noticed immediately that both dogs were very skinny. The puppy is a pitbull and I could easily see all of his ribs sticking out. He also walked around like he was terrified with his head down. The other dog was also very skinny I could feel all of her bones. By the end of their stay, the dogs were so comfortable and followed me everywhere, constantly playing and seemed very happy. The puppy wanted to constantly be touching me or sitting on me - when I was at my desk, he would jump up and just put his head on my lap to be near me.

One scenario that worried me - the puppy is not house trained, and one time he pooped on my carpet and I tried to pick him up just to move him to the tile floor and he FREAKED out. He ran to his sister on the couch and hid behind her like he was terrified of me. I quickly reassured him with a loving voice and lots of pets, then he was fine.

So, the owners came to pick up the dogs and the older dog ran over to them, but the puppy stayed attached to my legs. He has no interest in them and looked terrified. When they called him, he kept crawling behind my legs and staring up at me. I started walking inside and he kept following me, attached to my leg. The owner had to come pick him up to get him in the car.

Maybe I am thinking too much about this, but between his weight, the accident scare, and the way he reacted when his owners came to get him, I can't help but think he isn't being cared for properly. Am I crazy? Should I do something? Any advice is appreciated.. the dogs are the sweetest and I hope they are being cared for fully.

Thank you!