Well to simply end this before it ever takes off (damn too late but oh well) got is usually defined as omnipotent which is defined as being able to do anything that is logically possible. In other words it would be contradictory for even a deity to be able to do something that contradicts itself (such as this case) which is why most consider him to be omnipotent instead. Same argument with all-knowing. Like the common conception of all-powerful, the instead consider him to be omniscience where he is able to know everything that is possible to know without the mistake of logical contradiction.
In other words the argument against this has always been that god can contradict himself when in reality that would suggest that god is above those rules. Problem with the dissenters arguments it that if he were above this then he would indeed not follow worldly rules to begin with (which isn't a great argument against but a nice rebuttal). Second what they are staying is simply focusing on a single case of the instance. Such as this one provided, they can rebuttal that for a simple scenario but once the distinction is made they have no argument against what is stated. Basically that argument doesn't deny the existence of god yet simply shows that it needs clarification (while still working with the original argument) as mine has proven so easily.
So do tell your friend this and I'm sure he'll shut up quite quickly. That or he'll simply go back to the original scenario despite being defeated which is of course illogical.










