Is this a total parenting fail?

Our neighbors have 11 and 7 year old kids. Their 11 year old is on an art field trip today (as is mine) and won’t be home until 6:30, but neither one of the parents are home. This means their 7 year old came home to an empty house and had to come ask if he could stay over here for a while.

WTF? What kind of parents know their oldest child will be gone, and let their 7 year old get off the bus alone, for God only knows how long?

Is this a parenting fail, or am I overreacting?