I know we have "first boom confirmed" but I'm wondering if it also has something to do with the Russian Double Agent who was "poisoned".
Was this a cyanide suicide? Pretty easy to cover it up as a "poisoning" and would also link to Q's prior black hat cyanide suicide post. Plus it could prove to be worthy of a major "BOOM" once its determined who he was and why he was significant. (sorry didn't look hard enough to find the tag to Q post about black hat cyanide suicide - wanted to get this into discussion for revision of plausibility)
Just a thought, shoot it down if I missed something/misinterpreted or build it up if you have more to add!