It would mean that they are stalled due to CONTINGENCIES;
They are under CONTRACT, but the Contingencies have ot be satisfied to proceed further.
There is a chance that it will fall out of Escrow:
Have your Realtor contact the Listing Agent, and find out if it would do any good to provide a BACK-UP Offer; sometimes they will hold it, and sometimes it will go in the Circular File.
In any case; I wouldn't hold my breath, and that's what people do with a Back-Up; they are afraid to look at other houses, or make other offers, for fear that their pig-in-a-poke will come thru.
I would tell my Client to MOVE ON.
Good luck and may God bless