"Out 3 months" mark on passport

[Hopeful0820]

My wife was sent to China to work on a temp project for 3 months by her company (a S&P 500 company). She was still a US employee when she was there. Yesterday when we came back to SFO, the officer asked how long she had stayed and she said 3 months. Then the officer said "do not stay too long abroad" and my wife answered "I know". She did not mention the fact she was working on a temp assignment for a US company although she probably should have. Then the officer marked "out 3 months" on her stamp on the passport. (He marked it on mine first but crossed it out after realizing the mistake since I had only been out for 1 week.) Do you guys see any problem during next entry for her, although the mark was simply stating the fact? She is not expected to make any more long term travel but will probably visit family in China for a couple of weeks every year. I will ask her to bring the US paystubs with her during this 3 months for her next trip abroad. Other than those, any other caution needed? Thanks.

 

[Catseyes]

My personql opinion is that everything's fine. I mean, she was gone for 3months, which is less than the 6month limit. And it's not that close to the limit , not like 5months and 2weeks.
He just stated it.
Besides, if you said it is the only time ( she won't do that for years like some GC holders want to do ), there is no need to worry.