BU mechanics

[DTQ_Blue]

I was traveling out of state this w/e and dropped in on a HS game in the 5th inning. It was a post season varsity game involving large public schools; good quality of play. Of course I watch the umpires more than the players. On the several occasions when BU was on the line and came into the infield he never looked toward first base to observe a touch or possible obstruction by F3. The PU may have been looking for these things, but I'm not aware of any system that gives those duties to PU. Does any system teach that mechanic, i.e., that BU does not watch the touch and OBS at 1B? I do know that if there was OBS or no touch BU would not have seen it.