When examining the vehicle damaged by the first boy's vest exploding, Sam removes a shard of bomb residue from behind the front left tire. But the explosion was in the front of the vehicle, so there would have been no way for the shard to appear behind the front left tire.
Deeks makes reference to Nadir, Karim and Tomar Zahavi as being triplets just like those from surrogate mothers. The three boys, played by the same actor, are obviously identical, while the frequency of multiple births from surrogate mothers is the result of multiple eggs being implanted in the womb, with the babies being fraternal twins, triplets, quadruplets et cetera (assuming all the eggs are from the same couple).
All the boys with bombs are purportedly raised in rural India, have only been in the U.S. for two weeks, and were raised so cloistered they don't know what Netflix is... But they all and one have American accents.