Yes, that's right. I had always assumed "scot-free" meant unscathed, or perhaps a reference to Scottish border reivers getting away with someone's cows, but it seems this "scot" was an Anglo-Saxon word meaning a tax or compulsory payment.

Seamus C put up an intriguing post on 23rd May about the Gaelic word "scoth", and it hardly seems possible that it doesn't fit in somewhere (mind you, I don't know what scoth sounds like). The Vikings nearly took over Ireland at one point, though I think they were mainly Danes rather than Swedes; could Gaelic "scoth" be a loan-word from a Scandinavian language? Are there any Scandinavian words found in Irish? Is this a shocking example of blatant thread-drift?