The right sentiment, but not entirely true, actually. Some SQL injection bugs are only exploitable when a specific dialect of SQL is used under the hood. Some support query stacking (MSSQL), while others don't by default. Some allow for easy creation of files on the server's filesystem (MySQL), some don't. It's not exactly the norm, but also not uncommon for the behavior of a SQL dialect to mitigate a vulnerability. Not that one should rely on such behaviors for security, but it can assist.
That's not to say this is a case where a different version of SQL would have helped, of course. I haven't looked at the details.