Core book, page 59: The probabilities for pushed rolls are off. It looks like they were copied from MYZ, wherein one cannot re-roll ones, but that's not an issue in Alien. See this thread here:
viewtopic.php?f=50&t=3139&p=31726
This affects the starter set as well.
FWIW, the pushed roll percentages should be identical to the percentage of the regular chance of success for twice the dice. E.g., the chance of success with a pushed roll for 4 dice is the same as the chance of success for 8 dice (without pushing the roll).
It's also not clear what it means when it says that the pushed roll column includes the use of stress dice, since the table itself doesn't indicate how many stress dice would be added to the roll.