You cannot forget basic things while entering a country. How can he say he forgot to get visa for his kids when they are not Indian nationals. Yes it was wrong to have given the french national 2 days transit visa on arrival, which he should have applied in france. But that does not make the wrong of forgetting the visa for kids right.
Will France or US permit Indians to land in their coutry if Indians forget their visa. NO. So what the immig. did was correct.