Part 1 discussed friendly fire of users, this is quite understandable. Part 2 is about friendly fire of fellow team members. This to me, is often unavoidable but less palatable.

Dual- Write is a technology that will require collaboration between team members. Dual-Write will require
Dynamics 365 F&O knowledge, Dynamics 365 CE knowledge and Dual-Write knowledge. Thus usually at least 2 or possibly 3 contributors.

I heard of a time, a team was working on a task requiring the creation of a new table / entity in F&O,
and similar table in CE.
The fact that it was a new table, currently means the user that initially linked the tables, will need to add the table map. (I have it on good authority that this restriction will be dropped).
A service account was used but only a couple of staff has the credentials. Thus in this example, 3 team members were required to collaborate.

• F&O consultant created the new entity in F&O.
• CE consultant created the new table in CE
• User with service account credentials mapped the table in Dual-Write

The initial part all went well. However, an error occurred during the process of updating integration keys, save and mapping the fields and trying to Run the mapping.

A few issues had been identified and fixed :

• The Key of F&O was an integer value
• The key value in CE was changed from Text to Integer.

The issue still remained and then

The blame game started to appear:
“missing something in CE?” (F&O consultant)

The CE consultant then:
Takes screenshots of a similar table being created. Including fields and the keys. And requests the F&O consultant to review the related entity in F&O.

Resolution:

The F&O Entity Key had not been created

Summary:
Dual-Write will require collaboration between different team members.
All updates should be performed and shown to other team members.
This will allow multiple eyes over any potential issues.
Refrain from any Blame Game, it just may come back to bite you.