Sack totals are misleading, it's pressure on the opposing QB that is the real stat worth paying attention to for the most part.
The Irvin haters are going to hate regardless of what he does and will find any reason to justify their complaint that they don't think this player was worth the selection, is a bust , is stupid , they don't like him, etc..
Those two late sacks my be the early signs of a defensive turnaround. The team needs to be forcing the pocket more on the interior and when that happens the edge guys can go for it and bring the heat. The pass rush was significantly improved last weekend, if the progress continues the team will start to se the benefits of that pressure.
I suspect that Irvin will now see more time as a Leo than he has so far and that will pay off in pressure that makes a difference on the turnover differential. Each of our DEs needs more help from the interior DL though and if that happens suddenly the D will reassertion itself as the clear best D in the NFL.