Processing example files with roxygen2: backslashes are duplicated (\dontrun becomes \\dontrun)

Actual question

How can I avoid that \dontrun{ in a separate file containing examples becomes \\dontrun{ in the respective Rd file after roxygenizing?

I did find a workaround, but feel as if I'm maybe just missing something obvious, i.e. some setting of roxigenize().

Details

I think I noticed a possible bug or, IMHO, at least an undesired behavior when processing examples with roxygen2 that are stored in a separate file (as opposed to stating it right within the actual roxygen code).

The issue is that the line \dontrun{ in the respective example files becomes \\dontrun{ in the resulting Rd file after roxygenizing.

Below you'll find an illustration of the behavior along with a simple workaround

1) Ensure directories

dir.create("src", recursive=TRUE, showWarnings=FALSE)
dir.create("package", recursive=TRUE, showWarnings=FALSE)

# Ensure empty package directory
subdirs <- list.files("package", full.names=TRUE)
if (length(subdirs)) {
    sapply(subdirs, unlink, recursive=TRUE)
}

2) Create example functions with two different ways of embedding examples

foo1 <- function(x) {message("I'm foo #1"); return(TRUE)}
roxy.1 <- c(
    "#' Title foo1()",
    "#'", 
    "#' Description foo1().",
    "##' This line is commented out",
    "#'", 
    "#' @param x Some R object that doesn't matter.",
    "#' @return \\code{TRUE}.",
    "#' @references \\url{http://www.something.com/}",
    "#' @author John Doe \\email{john.doe@@something.com}",
    "#' @seealso \\code{\\link{foo2}}",
    "#' @example inst/examples/foo1.R"
)
ex.1 <- c(
    "\\dontrun{",
    "foo1()",
    "}"
)

foo2 <- function(y) {message("I'm foo #2"); return(FALSE)}
roxy.2 <- c(
    "#' Title foo2()",
    "#'",