I know ....
they're in a hurry to get information, but why wouldn't Wells arrange for Jericho to stay wherever he was after the implant, just in case the memories came back. Wouldn't Dr. Franks make that suggestion? Why would they think the effect would be immediate. I don't recall him ever saying the rats' memories came back immediately in his experiments.
Of course there wouldn't have been a movie if they'd waited, he coughed up the memories, didn't escape etc etc... LOL