If so, what if the fusing malfunctions and the plane crashes after running out of fuel? Does the Reich get an A Bomb gift?
That requires, as Michele stated above, that all fuses fails and the aircraft lands relatively intact... Not impossible but highly unlikely.
Of cause, with an intact A-Bomb at hand the Germans are probably gonna be keener on taking it apart and trying to learn from it than blowing it up, well, it would provide useful pointers for the Germans (e.g. that you only need a few kilos of enriched Uranium to Plutonium to get a boom, rather than the 100s of kilos the Germans believed IOTL; some rather useful pointers on which A-bomb designs are workable and things like that), but the German A-Bomb programs was far behind the Allies in OTL, so they'd need time to catch up and fully understand the whys and hows of weapons construction which likely means at least six-months to (much more likely) years before they can successfully clone the bomb.
On top of that, they lack the enrichment infrastructure to produce a useful amount of enriched uranium or a reactor to produce a useful amount of plutonium, the time to develop the necessary tech and build the infrastructure to do either of those means they're limited to the fissile material they can extract from the captured weapons for at least a year, more likely two or three after the bomb falls into their hands.
So, reverse engineering the bomb puts any plausible German A-Bomb well after the Western Allies and USSR meet on the Oder.
Using the bomb? Deployment by bomber against a British target is out due to the weakness of the Luftwaffe's bomber arm by 1944 and the strength of allied air defence. Deployment by bomber out East could work, but the yield of a 1940s weapon is relatively low and by '44 soviet industry is relatively dispersed, so poor odds of slowing them down short of taking out Moscow... and that probably means taking on the best air defence the soviets' can put up, and at fairly long range. Using it as a landmine against troops on either front? You vaporize maybe three divisions... Not gonna slow either the west or the soviet down for more than a month or two. A U-boat based attack on US port could work but is risky and will only serve to piss the Yanks off even more while barely harming their industrial capacity...
Yeah, none of those look like a winning move...