1-4 family residence purchase application; credit was pulled; no income and other information also missing, so no decision was made. 2 days later customer says deal fell through. Is this HMDA reportable? They didn't really withdraw it, but it was also not denied for being incomplete. What would you do?

I would consider that withdrawn.

Agreed, no adverse action was taken. In this case, from what you say, a decision on whether to grant credit had not been made.