No, that isn’t what Gowdy is saying please read his quote in his own words again.
“In the last week, we have seen a systematic effort by Sen. Cruz and his allies to spread false information and outright lies in the hopes of winning votes by appealing to our lowest common denominator,” Gowdy said.
He is accusing. Can’t get any more plain than the above quote
Nowehre in that quote is an accusation that the Cruz campaign created the fake facebook posting. If the posting is false, it costs Cruz nothing to say so.
UPDATE (3:24 p.m.): Responding to Gowdy's comments, Cruz spokesman Rick Tyler criticized the Rubio surrogate for "throwing around wild accusations without any evidence whatsoever," pointing specifically to the Facebook page, which he said the Cruz campaign had nothing to do with
Show me where Gowdy accused the Cruz campaign of erecting the facebook post. I don't see it in the OP.