Probably not but 1) if you can't prove a quid pro quo then why was he impeached? Also apparently the house 2) did not follow proper supena process by holding a vote and 3) taking executive privilege to the court. This whole thing seemed rushed and not fledged out tbh.
1). Imagine withholding all the evidence and then saying prove it.
2). That's a minor technicality and using it as your entire defense is foolish.
3). You don't need to take it to court. Congress has the sole power of impeachment and in the US vs Nixon (1974), the Supreme Court ruled that executive privilege does not have priority over an impeachment proceeding.
1. In a fair investigation or trial lets say someone allegedly assaulted someone but if the person that was allegedly assaulted says that they were not you have no case. You're innocent til proven guilty and if the Ukraine government is saying they had no idea aid was witholded you can't prove a quid pro quo.
2. Thats proper procedure and them not doing it comes across as rushed.
3. Oh okay if that's the case then I do see the case for impeachment under obstruction of justice.