Look at #67 and where his assignment ended up - a yard in the endzone. That's bulldozing.
That's why I am saying you don't know the scheme that was called. If it was an inside run, Bell did what he was supposed to do. You can see an extra block on the TB number 45 (looks like one of our TE acting as a FB) to the inside. And the WR is not even attempting to engage the CB to block him. All this and Bell's technique tell me it's an inside run. When the running back cuts it to the outside, you can't blame Bell for "not sealing the edge" just like you can't blame Kalil for his assignment recovering the fumble.