1 {scene: The prison cell. Monty is lying on his stomach, digging. There is some rubble on the floor around him.}
1 Prof. Jones: Someone's coming! Quick, Junior, cover up the tunnel entrance!
2 Erwin: Die Führer says he wishes to see die archaeological expert...
2 Monty: I guess that's me. Lead the way, Erwin.
3 Erwin: ... on Atlantis. {opening Dr Smith's cell} Fraulein Doktor Smith, follow me please.
4 Monty: {after Erwin and Dr Smith have left} Hitler did that on purpose. Psychological warfare.
4 Prof. Jones: He's quite the brain, you know.

Monty's first line was originally just, "I guess that's me." But I wanted it to be obvious that that's Erwin asking Dr Smith to follow him, and not just Nazi 1. So I added the line in post-production (i.e. while I was setting the dialogue in my graphics program).

I often change lines slightly when I put a strip together at that stage of production, as it gives me an extra chance to review the dialogue and tweak it to make it hang together better, or make it funnier, or make it more obvious what's happening.