Wrong ConvertedType at "params" parameter?

[domoszlai]

Consider the following methods:

public static string Format(string format, object arg0);
public static string Format(IFormatProvider provider, string format, params object[] args);

on invocation:

double r = 2;
Format("{f:5}", r);

At "r" GetTypeInfo gives

Type = System.Double
ConvertedType = System.Object

But

Format(provider, "{f:5}", r);
At "r" GetTypeInfo gives 

Type = System.Double
ConvertedType = System.Double

Accordingly, in the first case ConversionInfo says Boxing, but Identity in the second.

I would expect the same in both cases. Am I wrong?
I use Roslyn 1.0