No it wont scare him off.
there is almost always several deer under my feeders in the morning when it goes off.
it always spooks them and they run, and Most of the time they come right back in 5 minutes or less.
Sometimes they dont, but even the ones that dont come right back, will always be back another day.
it just happened that that particular day, you 8point buck just wasnt in the mood to go back.
SPOOKING a Deer, rarely scares them away for ever.

Examples: Shooting at, and missing a Deer... just to have that same deer come back 1 hour later to give you a second shot.
i have had this happen a few times.
Or.. when there is 5 or 6 deer out there, and you shoot and kill 1.. and the others go crashing through the brush.
Most of the time, all those same deer are back under that same feeder within 24 eating, like nothing ever happened.
of course this may change by LATE SEASON if this happens "several" times.
usually they keep coming back, they just stare in your direction longer and act a more skiddish.