Vol 4: Ch 242 - It might be someone from the Din's Family
Before the whole incident and the death of Meng Xue, Officer Lin automatically got up from his seat then give the signal to his kids that they directly escaping under the table and go to where Din's Family seated while giving the signal he hid his wife under him or rather of the back of him and said mumbly to his wife that enough for her to hear it only.
"We will be alright sweetie" then notice that both his Dad and the newly found man of his sister-in-law also did the same thing as what he did for Feng.
As an Officer, he feels it's a failure to protect them but at least before picking up the kids, he notices a similar figure and feature of Xue so that's the reason why he gives that signal to his kids even though he wasn't sure if it's her or not but he still warns the kids just to be safe.