Chess engine "analyzing" 2 moves with different result

Hey,

I don't know what is the problem with the engine, but it shows different results for same 2nd move.
https://i.gyazo.com/70c0106b14fb9f33e43a749b26f37de9.png
https://i.gyazo.com/6f684f3e4a183bc226e192b67a547aa3.png

In one case it says that it's a "mistake" and the other that it's a "book move".

How can I ever trust the chess engine to analyze any game with "brilliant"/"good" moves and what not if it fails at the very beginning.

Book moves are determined by whatever is coded in the review code as a book move. That said, a book move can still be a mistake, from an evaluation standpoint and will differ based on depth.

You cannot trust an engine in the early opening. There are too many possibilities so the horizon effect prevents an accurate evaluation.
It is normal for two different engines or for one engine with different time to give different evaluations.

What do you mean by a "different time"?

@4

Different calculation time.