JNJ can't remove the post. It's common knowledge that it was posted, and there are probably 30 copies of the ad ready for immediate reposting if JNJ were to take it down. So why bother? Besides, if they take it down, then they have to explain why they took it down. Now they have to explain an explanation. The JNJ story goes from barely plausible to just ridiculous.
They have no choice. They have to live with the ad as it was posted and hope their Bloomberg explanation flies. This is the optimal strategy when a mistake like this is made. We should expect that a company like JNJ would know that and act as they did.