I Liked the Ending
This was no Liam Neeson revenge thriller. And as such, there is not the usual predictable ending after a bad guy has been dealt with. No wise crack retort before someone is blown away, and the good guys riding a motorcycle off into the sunset.
This felt REAL. You can tell Matt will not be sleeping for quite a while. He's already possibly regretting what he's done, or at the very least, wondering about getting caught. Will there be forensic evidence, eyewitnesses, surveillance cameras? Will it all unravel next month? Maybe in 5 years or a decade? He just added a huge amount of baggage to be carrying around for the rest of his life, and you can see it all on his face.