How did this match I played end in a draw?

FIDE Laws of Chess 9.2
The game is drawn upon a correct claim by the player having the move, when the same
position, for at least the third time (not necessarily by a repetition of moves):
a. is about to appear, if he first writes his move on his scoresheet and declares to the
arbiter his intention to make this move, or
b. has just appeared, and the player claiming the draw has the move.
Positions as in (a) and (b) are considered the same, if the same player has the move,
pieces of the same kind and colour occupy the same squares, and the possible moves of
all the pieces of both players are the same.
Positions are not the same if a pawn that could have been captured en passant can no
longer be captured in this manner. When a king or a rook is forced to move, it will lose its
castling rights, if any, only after it is moved.

In this case positions after moves 34, 36 and 40 are identical hence draw.

Move 30 Qg5 was a blunder, where knight could have gobbled the white queen.

or the black one

It's a draw by threefold repitition, however white is clearly winning if not for blundering into repetition. Also the queen was hanging on moves 29 and 30 simplifying to a little more easily won position up a queen vs up a rook.

It is still classed as 3 fold repetition even if the position changes inside the repeated position.