In my opinion, the reaction to this particularly large pull was probably a combination of several things. Perrin's sense of duty perhaps could have taken effect, but as you yourself said he already had a valid reason to go, which outweighed the reasons to stay. I think it was a combination of how new they were to the powers, the simple force of Rand's tavern, nd finnally distance. As stated several times throughout the series the power of saiden/saidar was greatly reduced at distances, it would seem logical that the wheel, or the thread of the wheel that represented Rand althor would also lose potency at a distance. The obvious question to follow this train of thought would be why then did not the pulling increase as distance closed? The answer is simple.. there was no need for it to. By that time it had already accomplished its task.