This article explicitly disclaims the idea (with claims to authority) yet is evidence that we are currently experiencing an unusual cluster of volcanic activity.
http://www.wired.com/2016/05/please-dont-blame-mars-weeks-explosive-volcanic-eruptions/
The possibility that there are physical processes going on that we don’t understand is not zero.
Well, not zero, but about as close as you can get without it being zero. That recent comet flyby had more gravitational influence than Mars. Gravity is pretty weak.