Hoffman smashes some guy over the head with an unsprung bear trap. He isn't really seeking vengance, rather making a stand. The local lowlifes from town who picture him some kind of subhuman want to torment him and destroy his home under the auspices of bringing the retarded fugitive he's housing to justice.
Creutzfeldts's Jacobs disease is right. He,Hoffman wasn't seeking vengence,but while standing his ground he did kick ass. Interesting side note I noticed,the retarded fugitive in "Strawdogs"
also appeared in a very good Peckinpah film "Cross of Iron" as a disillusioned Whermacht officer,adjudant to the regimental commander