I think we can all agree that this was a cringeworthy title, but does Adidas at least get points for accuracy? I know it's probably not a good idea to imply that survival was in question during the one annual event in which innocent people tragically passed away, but - despite being completely inappropriate given the circumstances - the multinational brand wasn't technically wrong.
I suppose they could have done a better job than crafting a congratulatory cliche off an unoriginal novelty tee shirt in a way that didn't remind people of a terrorist attack immediately following their huge personal milestone. However, if there's a form of communication that is constantly plagued by poor wording then it's e-mails. Some will say this is a stupid, inexcusable mistake to make, but Louis C.K.'s recent standup special included a bit about needing an entire team of people to help him write his e-mails and he's a comedic genius. I genuinely think someone could finish a flawless thesis paper, and somehow spell their name wrong in the signature when sending it in. It's a weird phenomenon, but it's one that exists nonetheless.
In all seriousness, isn't it pretty easy to find out if this semantic disaster was on purpose for publicity? There are dozens of marathons throughout the continental United States, and I highly doubt Adidas only sponsors one of them. If this dumb ass header was only sent out to those that completed the Boston marathon then it was 100% intentional. If it was just something that went unchanged from a previous time that Adidas shamelessly tried to get people from another city to buy new shoes after wearing out their old ones by running 26.2 miles then it was an unintentional non-act of laziness. Seems pretty cut-and-dry to me. Someone needs to contact a person that travels to run for fun and see if their "you did it!" messages from Adidas match up.