Just watched it on a famous video website which Trinity posted the video on. You are absolutely spot on bren2k after seeing that. Both Mathers incidents were purely competitive with no malice, just 50:50 incidents. The Fox incident looked the worst of the three. By the freak of chance Fox was the only one of the three to not be injured from it.
To be fair to Rovers, watching the second half kick off the ball did not look to be anywhere near Dobson's foot so they were unlikely to be given offside. Having said that, even on the highlights video there is lots of evidence of players offside (e.g. Rovers supposedly defending when stood on their own line) and defending players not standing square. Nothing new, we see it every week now, just not applied consistently.
Looking at the highlights I think Agar enjoyed it more than anyone else when he came on at the end!