The Bills loss was no death knell for John Harbaugh, according to Jamal Lewis ... who tells TMZ Sports despite the bad defeat, the Ravens shouldn't consider canning their head coach.
Of course, a bunch of Baltimore fans felt much differently on Sunday following the 23-20 L ... as the Ravens had all of the chances in the world to pull out a victory.
They were up 20-3 late in the second quarter ... and despite blowing that huge lead, they still had opportunities at the end to pull it out, but didn't.