The simple answer is that you write down the result as it happened at your table: 3NT-1, declarer E (or W), NS +50 (or +100 if EW were vulnerable). For the TD, it's a little more complicated than that.
This is a fouled board. It has to be matchpointed in two groups: the first, those who played the board before it was fouled, and the second, those who played it afterwards. If there is only one table in the latter group (you played the board in the last round) then *both* pairs at that table get average plus (60% of the matchpoints or the pair's average on all the other boards, whichever is greater). See laws 86, 88, and 12. In addition, the pair or pairs responsible for fouling the board (at the table which played it before you) might receive a procedural penalty.