The NDP would have won Westmount-Ville Marie if you took only election day polls, which might explain why Marc Garneau conceded defeat on election night only to retract it later as usually the advanced polls are the last to come in. Also it was Westmount that saved him as the NDP came in third in Westmount behind the Tories.
When it comes to strictly e-day, how many seats "voted differently", besides Sask-RB and West-VM?
When it comes to St Kitts at large, it never had the collective reflected glory of the Swart/Kormos provincial NDP powerhouse machine, the way that Thorold and Welland and now Port Colborne has. And the parts
within Welland riding also happen to encompass some of St Kitts' toniest neighbourhoods, thus nullifying NDP reach except in a few spillover spots. Otherwise, the most "NDP-natural" zone in St Catharines actually happens to be the south-of-the-QEW part of St Catharines riding, encompassing downtown as well as GM--but the riding at large is cancelled out by a historical lack of a strong, provincially/federally electable machine a la Welland; thus a lot of that vote's defaulted Liberal (notably Jim Bradley provincially) and elsewhere. (North of the QEW, it's mostly postwar-middle-class-suburban tedium that tends to be fairly solidly Lib/Tory--or just plain Tory as of the last two fed elections--though there *could* be orange-umbrella grand-coalition possibility there.)