Marine Core , Delayed Entry Program ( DEP )?

i have a question about the DEP , a friend of mines is in the marine core Delayed enlist program , but hes starting to get second thoughts about leaving his mom alone . can he still back out of the program at any time before boot camp even if hes done the first oath , i was told that doesn't matter aslong as he does not do the 2nd oath on that same day he ships out. and would this hurt his record at all??? for like applying at places in the future? i need Serious answers please , no " OMG hes a wuss "ect. ect.