I don't think it's the results that are causing the concern. I think it's that so far the results have be good given where we were but that what Sam has done is what we all knew he would be able to do. Make us tough to beat.
Now the concern is that he can't go beyond that. That was the biggest reservation for most people, he has a ceiling and we will remain tough to beat but unable to go beyond that. The way the last two games have played out is bringing out those fears.
He still needs time, a transfer window, and less fixture congestion to get his ideas across. It will be hard to keep fans onside with the footvall he is playing though and things could turn sour very quickly.