Shiel was referred directly to the tribunal after pushing Geelong opponent Mark O'Connor in the way of Lual during their 44-point loss to the Cats at GMHBA Stadium on Friday night.
An airborne Lual, making an attempt at an intercept mark, tumbled over the top of O'Connor and landed heavily on his head.
After a few seconds on the ground, Lual was able to walk himself off the field.
The Bombers newcomer returned to the game but was eventually subbed out at three-quarter time.
The incident was deemed rough conduct by the match review officer but not graded.
"A suspension of one match is the appropriate penalty having regard to both the impact to O'Connor," a statement by the match review officer said.
"And the significant potential that Shiel's teammate, Luamon Lual, could have suffered a serious head or neck injury arising from Shiel's unreasonable conduct, which caused Lual's head and neck to make contact with the ground with force."
The match review officer reiterated their position by stating the players owe "a duty of care to all other players, not just their opponents".
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