It's bollocks, take my word for it, the RAF are in (or were) the skies over Iraq/(near) Syria, on their normal regular patrols. Any missiles/drones will have only come from Iran over Iraq, and we'd have shot them down, as they were a threat to us.
Saudi/Jordan would have similarly shot any down that came over their territory, because they are a threat to their people.
Iraq probably wouldn't have the resources/time to do much (or probably give a shit to be fair), Syria (government) just wouldn't give a shit.
On a another note, any missiles reaching Israel will not be the first ever, as many reached Israel in the 2nd gulf war from sadam.