[Cookpad recipe vs. Ito] Mikan, Satsuma Mandarin, Bread

I baked the mikan, the satsuma mandarin, bread by following the recipe on cookpad.
According to the recipe, what ingredients I need to make it are:

強力粉 (bread flour) 280 grams
みかん４個（正味250 grams） (4 of the satsuma mandarin orange for about 250 grams)
砂糖 (sugar) 20 grams
塩 (salt) 5 grams
バター（マーガリン）(butter or margarine) 20 grams
スキムミルク (powdered milk) 8 grams

ドライイースト (dry yeast) 3 grams

   

I had everything except powdered milk. But, I know I could screw everything up by choosing the wrong substitutions (and actually I am very good at it,) so I did not use any substitutions either.   

I had the salt but I did not use it because the butter was not unsalted one, so I assumed what the butter contained should be enough.  

Then, I put everything in the container of the home bakery except the dry yeast; usually, most of home bakeries have the separate place to put the dry yeast in. 

    

   

For the quick mode, I put more dry yeast than the regular mode, so I put 5 grams of the dry yeast instead of 3 grams.  After I started the machine, I just need to let it bake the satsuma mandarin bread for some hours.   

And this is how it came out:

 
  

I am not sure what had happened, but the top middle part of the bread was dented. 

It could be because either the room temperature was too low, or Anpanman punched on it while I was not looking it.
  

    

   

Darn you, Anpanman.