Who was in the wrong?

Me, my husband and our 2 year old were at my sister's house visiting. We were out back, and I seen my husband playing with our son, so I go to have a quick chat with my nephew standing at the door a few feet away. Next minute I hear our son scream so I turn round and see my husband sitting on the chair looking at his phone and our son nowhere to be seen!! Our son then stood up and I ran over to him as he fell down some steps at the bottom of the yard. My husband then came over to us and I said "why weren't you watching him??" He turned round and said "why weren't you? There's both of us!" I just ignored him and calmed our son down. I'm so angry, my husband could visibley see me chatting so why would he leave our son to run around himself with hazards like steps? To go sit on the chair and look at his f***ING phone!

*Please settle this, who was in the wrong?

Ps after this I would not let our son out of my sight, then I went to the toilet quickly and came back and my husband said "can you take him so I can get some peace?" 🤬🤬 Like wtf, I was gone for 5 mins!!