Newcastle is definitely strong, this everton game was a fluke by them and I am sure they will do just fine. We also need to remember that they are seventh, not like they are at the very top, this doesn't mean its usual for them to lose to Everton, but there are like at least 10 teams that wouldn't shock the world if they beat Newcastle, sometimes its normal for teams to lose, its not really a big deal. I think they may end up with another loss, Tottenham started the season amazingly, maybe not doing all that great recently but they are definitely a tough team to beat and unlike Newcastle they are closer to the top. Lets see how they will do, but I would give the edge to Tottenham there.
In football there really is no such thing as a coincidence for me, A defeat is still a defeat and that doesn't mean we should consider Everton to have won by luck in this case because they also played very well in this match and Newcastle did have problems especially for the defense in the second half.
The mistake made for this first goal made them immediately make many subsequent mistakes including a failed offside trap that made Everton 3 goals ahead.
This needs to be corrected and indeed their performance is still very good, it's just that there are still some weaknesses that they must fix.