It shouldn't matter even if there was a notation... the agents in LGA could've looked at the history and see how the original ticket was issued and the flights you were on, along with subsequent rerouting.

You should also have your original tickets/PNRs as purchased, and receipts in your DL account online to show the flights you were on before the MX.

Anyway, yes you should've been provided overnight hotel accommodation and you should get reimbursed for that.