The issue is not whether it is appropriate to ask Ukraine to look at possible corruption by a US citizen. The issue is whether it is appropriate to slow down $millions in military aid while Ukrane’s soldiers are dying. Then asking the new Ukraine president to make a public statement that this investigation will be done, either saying or implying that the military aid will be affected by a public statement.
Makes sense.
Until the Ukrianians go on record that they’ll purge corruption, the Ukraine should not get a single dime of US taxpayer money.