I tell everyone these days....it's not done until it is done.
Don't count the money in the bank until it is in the bank.
The typical Texas contract has lots of outs for the buyers.
It is great when you buy, terrible when you sell, but that is the way it works.
Not only can the buyer get out, but there are times when loans don't close and lots and lots of other issues.....typically the further into the contract you are the more secure it is, but nothing is done until it is done.