transactions between two databases different instances same sever

Hi, I'm searching considerations and opinios involved in transactions between two databases and different instances. The reason is that a few day ago our server were stopped in hot and some operation between this two instances didn't make a correctly rollback in my opinion. I have a process in which in certain point inserts a row remotely from instance A to an instance B, and this row inserted has a field that is copied as a reference informative to another table in instance A. All this is framed in a transaction. I realized that a row was inserted on instance B, but reference is not in its corresponding table in instance A. I appreciate your help.

Why was in not in instance A? Did instance A crash? Didn't the message log on A or B mention a heuristically rolled back transaction? Or the startup message say that there were open transactions or bad locks? You should get a message somewhere and reading the manual would tekk you that you need to use onlog to examine the transaction log and manually fix any inconsistencies.