Smith has been called to attend a Rugby Football Union disciplinary hearing on May 2 after being charged with "conduct prejudicial to the interests of the union and the game".
The Australian is understood to have been furious at referee Nick Williams and touch-judge James Minards over their handling of a second team game at Gloucester, which London Irish 'A' won 12-7 in appalling conditions.
The minimum entry-level suspension for a coach found guilty of verbally abusing match officials is six weeks which means Smith would be confined to the stands just as the Exiles' season reaches its climax.
Smith has guided London Irish into the last four of the European Challenge Cup and, with just three league games left, they sit on the brink of a Premiership semi-final.
But any ban of at least four weeks would cover both the Premiership semi-final and Grand Final plus, should London Irish beat Newcastle, the European Challenge Cup final as well.
Smith would be restricted from any match-day coaching. He would be banned from the touch-line, the tunnel and the changing room.