Question on Hiarcs15jBook

[KLc]

Consider 1.e4 c6 2.Nc3 d5 3.e5?!. Hiarcs15jBook now shows 2 moves: 3...d4!? and 3...Bf5?. There must clearly be a best move in this position, why is there only a move annotated as speculative (!?) and one as mistake (?). [I also find it quite harsh to consider Bf5 a mistake here...]

[gads]

Bf5 is shown as ?! not ?

[KLc]