He said that at least one other Democrat, whom he declined to name, also might be interested in running.
If the Democrats still can field a candidate, they will, Metzner said.
Maryland's Election Law lets a political party pick a replacement to fill a nomination vacancy. For this year's general election, the deadline is Oct. 4.
However, the vacancy provision only applies to replacing someone already on the general-election ballot, said Donna Duncan, the director of the election management division at the state board of elections.
A party can't add a candidate for the general election now if it previously had no candidate, she said.
But Roger Schlossberg, the attorney for the Washington County Board of Elections, said the statute isn't "crystalline."
He noted that Election Law doesn't define "vacancy," leaving it open to interpretation.
"If some interested party wanted to take this to court, I do not think the conclusion is at all foreordained," Schlossberg said.
Part of Election Law says: "If a nominee for an office that is entirely in one county dies, declines the nomination, becomes disqualified, or gains a tie vote with another candidate in a primary election, the vacancy in nomination shall be filled by the later of: (1) the 40th day before the general election; or (2) the fifth day following the death, declination, or disqualification of the nominee."
However, a previous subsection refers generally to a "vacancy in nomination" without defining it or giving a time deadline, causing Schlossberg to question the statute's specificity and clarity.
For about a day after his GOP primary defeat, Munson considered additional ways to try to beat Shank, such as seeking a Democratic Party nomination for the general election or trying a write-in campaign.
He later backed away from those ideas and conceded that Shank had won.
People have until Oct. 27 to file a certificate declaring themselves write-in candidates for the general election.
Patricia Heck, the Washington County Democratic Central Committee's outgoing chairwoman, couldn't be reached for comment Thursday.
Donnie Souders, a former committee member, said he's familiar with recent committee discussions and the idea of trying to place a Democrat on the general-election ballot to face Shank hasn't come up.
In May 2009, Washington County Commissioner Kristin B. Aleshire, a Democrat, announced his interest in running for the District 2 state Senate seat after Munson retired.
Asked Thursday about Munson's defeat, Aleshire said the Democratic Central Committee hasn't talked to him about the Senate seat and he isn't interested in a write-in campaign against Shank.
As a husband and father of two, he said being a senator doesn't fit in with his family life now, but he might consider a run in the future.