What did she mean?
Answer: She meant “send it to the client.” Which is what she should have said instead.
The concensus seems to be that “throw it over the wall” means to transfer something from one individual or group to another, with the implication that the first person or group has finished with it. I think the metaphorical reference must be to the act of lobbing things over the wall of a fortress, as seen in historical movies. In all the examples that I saw, things were thrown in an effort to drive off attackers, so it was things like boiling oil, or rocks, or flaming objects. However, the metaphor doesn’t seem to extend quite that far.
In its entry for “throw it over the wall,” Word Spy cites the earliest use :
“We need less of the grunt-and-grind applications systems which we’ve gotten so good at building,” he said. However, “putting tools out there isn’t enough,” he added. “You can’t just throw it over the wall and expect them to use it.”
—Bruce Hoard, “IBMer Calls Demand Processing Wave of Future,” Computerworld, January 19, 1981
On Forbes.com, authors Max Mallet, Brett Nelson and Chris Steiner include “over the wall” in The Most Annoying, Pretentious and Useless Business Jargon. The article recounts the story of a PR account executive whose boss asked her to throw a document over the wall. She eventually had to ask him what he meant. The article’s authors’ recommendation: “If you’re not wielding a grappling hook, avoid this meaningless expression.”
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