Some operations do not ignore trailing dimensions equal to 1

As in the title. Here is a small example:
addition in Base Julia arrays ignores trailing dimensions equal to 1:

julia> [1 2][:,1:1] + [1]
1×1 Array{Int64,2}:
 2

but in StaticArrays it does not:

julia> [1 2][:,1:1] +  SA[1]
ERROR: DimensionMismatch("Sizes ((1, 1), Size(1,)) of input arrays do not match")
Stacktrace:
 [1] _throw_size_mismatch(::Array{Int64,2}, ::Vararg{Any,N} where N) at /home/mateusz/.julia/dev/StaticArrays/src/traits.jl:198
 [2] same_size at /home/mateusz/.julia/dev/StaticArrays/src/traits.jl:192 [inlined]
 [3] macro expansion at /home/mateusz/.julia/dev/StaticArrays/src/mapreduce.jl:74 [inlined]
 [4] _map at /home/mateusz/.julia/dev/StaticArrays/src/mapreduce.jl:41 [inlined]
 [5] map at /home/mateusz/.julia/dev/StaticArrays/src/mapreduce.jl:34 [inlined]
 [6] +(::Array{Int64,2}, ::SArray{Tuple{1},Int64,1,1}) at /home/mateusz/.julia/dev/StaticArrays/src/linalg.jl:12
 [7] top-level scope at none:0

Do you think StaticArrays should have same_size modified to follow the behavior of Base?

Start with src/traits.jl at same_size and _throw_size_mismatch, then read the callers shown in src/mapreduce.jl and src/linalg.jl. Compare the reported StaticArrays behavior with the Base Julia example and determine whether trailing dimensions equal to 1 should be accepted; done means the operation follows the intended behavior without the reported DimensionMismatch.