During his ascent, two deer ran in front of him, and McCurrach heard several stags roaring.
Meanwhile the soldier had been resting with two friends on the Sparrowhawk bivouac track.
McCurrach saw movement and shot and killed Jordan instantly with a single shot to his neck from a distance of 42m.
Bullet fragments injured Jordan's friend, and these fragments remain in the man's leg as it would cause more damage to remove them.
A dog was also hit by fragments.
Jordan's hunting began yelling before activating an emergency locator beeper.
The defendant was said to initially be confused about what had happened.
He believed two animals had been before him when he fired.
He went with police to the station and had been fully co-operative since, prosecution said.
At an earlier court appearance, McCurrach's lawyer had sought a three-week remand so he could get a forensic optometrist report before his client entered his plea.
McCurrach faces a maximum three years' imprisonment or a fine of $4000.
Judge Rea ordered a probation report and remanded McCurrach on bail for sentencing in September.