I remember reading some of the comments saying that they were in contact about various backstories (for overlapping characters like Rampage). But I don't know of anything specifically said by either author that they were explicitly trading notes.
-Terry
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"so listen up boy, or pornography starring your mother will be the second worst thing to happen to you today"
TF2: Spy
-Terry
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"so listen up boy, or pornography starring your mother will be the second worst thing to happen to you today"
TF2: Spy