Is the action of one who doubted the number of Jamarat and based it on the lesser number, then completed the count out of caution, correct? And is the action of one who doubted whether two pebbles fell inside the basin and threw two more, correct?

Whoever doubts the number of pebbles he has thrown and bases his action on certainty, or doubts whether the pebble landed in the throwing area and repeats the throw, has done well and acted correctly.

Ibn Uthaymeen said: "There is no harm for someone who doubts whether he threw seven or fewer pebbles to throw extra as a precaution until he is certain that seven pebbles have landed in the basin."