In my humble yet honest opinion, I have less of a problem with his home plate business than with his 1B business. That was a dirty business. Clemens is stretched in a vulnerable position, concentrating solely on digging out the throw coming in, and that could easily have been a serious groin, hamstring, or knee or ankle injury waiting to happen. You're right, that was truly a BS play.
Watching him play soccer on that subsequent grounder was poetic justice.