An occasional spelling error is acceptable--we all have words that we spell wrong, alternative spellings, and typos (which are all too common and often easy to miss editing). But, when people have a hard time spelling throughout the whole of their web page, that betrays a blatant lack of education (and, by spelling problems I am not referring to terms that poke fun at organizations, alternate spellings, and the occasional typo, but simple words that are not spelled correctly throughout the page).
It is tacky to pick on an isolated error. It is not tacky to pick on widespread spelling errors throughout a whole document, as that betrays lack of education. Perhaps their children should be in bed instead of at the boasting session on Thursday evening, and they should be doing homework instead of out in field circus during the afternoon. And, they should be having fun instead of sitting through a Grand Boasting Session during vacation periods.