When Roger and the other prisoner are being marched back to the Mohawk village the other prisoner stumbles and falls. Roger shouts to the Indian in front of him "Stop stop!". This Indian then turns to the Indian in the front of the caravan and shouts "Stop!" in English instead of in the Mohawk language. The Indian understands this command and stops the caravan.
Claire says that she misses aspirin. This is an ignorant statement. Throughout the series Claire is portrayed as an expert on herbology and she is constantly collecting medicinal plants. Aspirin is derived from the bark of the salix variety of willow tree - which is found all over Europe and in North America as well. She would most certainly have known this.
Briana refers to Led Zeppelin. She left modern times in 1968. The band did not release its first album until 1969.