Reread lines 520-523. "His whole idea at first was to put distance between himself and General Zaroff, and, to this end, he had plunged
along, spurred on by... something very like panic.
How could "plunging along" in panic be problematic for Rainsford?
Although he is very familiar with the island, if Rainsford panics, he may lose his sense of direction
If Rainsford is panicking, he is probably not being mindful of the likely easy-to-follow) trail he's leaving
behind
If Rainsford is panicking, he might walk right by a magnificent walnut tree
If Rainsford is panicking, he may accidentally step on a black mamba snake

If Rainsford is panicking, he is probably not being mindful of the likely easy-to-follow) trail he's leaving  behind .

Explanation:

Richard Connell's short story The Most Dangerous Game presents a famed and expert hunter being hunted by an insane and barbaric general who prides himself in achieving an exciting form of hunting. Sanger Rainsford's attempts to save himself from the grasp of the insane hunter General Zaroff led to the inverse role of him being hunted despite being a talented hunter himself.

The given lines are from after General Zaroff told him to get along before he is pursued as a prey. Rainsford had to get to a safe distance if he is to stay alive and earn his freedom. And in his shock in discovering he had been selected as the prey to be hunted, he couldn't think straight which led him to have a sort of "panic". So, the "plunging along" in panic in the sentence can be problematic for if he panics, then it will mean he will not have a clear mind on how to misdirect his hunter. The panic will most likely keep him so occupied that he will miss making the trail difficult, leading Zaroff to follow the easy trail left behind by the 'panicking' Rainsford.  

whether dad arrives in time for the game depends on his conference. subject