then the race condition would be in the database.

A database alone is not a system that ends up in a race condition. You could have a race would be between the programs/processes/threads using a database, for example. The system suffering from the race condition would entail not the just the database, but those programs/processes/threads too.

then he could have a race condition.

I didn't say that forking couldn't lead to a race condition.

Can't tell unless we get more information.

I only said your claim that race conditions necessarily come from forking a Perl process was false. No extra information is needed for this.