In TMP, Kirk beams up from Command to an orbital base because the Enterprise's Transporters are broken. Minutes later, they decide to go ahead and beam up the science officer directly, and the transporter breaks again.
From my understanding of the Transporters, a pad to pad transport is still one-sided. If the Enterprise-D beams Spot to the USS Crazy Horse, it's the Enterprise-D's transporter that handles the transport; the Crazy Horse's transporter pads are just running like a beacon to more efficiently and safely land the kitty safely.
It's why the Klingons in Star Trek 6 have to command THEIR ship to beam them over; again, only one end of the transport is operating; in this case, the pads on the Enterprise are just an origin beacon, with the transporters of Kronos One handling transport.
Unlike, say, the transport failure of Half-Life Two, where you get a real sense that both ends have to coordinate to successfully transport, in most cases on Star Trek you really get the feeling that one side is in control, and the other side is just a target.
...except when we needed to murder the imposter Spock so we could pick up the real one on the way to V'Ger.
During the transport failure, both sides are snapping at each other to resolve the transport; we get the strong feeling that one side handled the disintegration, while the other end handles pattern processing and re-integration.
This leads to an A/B set of questions:
A) If both sides need to handshake to handle transport, why did they test it on the Science Officer?
We've seen multiple times Transporter Test Objects in TNG, and always hear about diagnostics and the like... so why is the first thing beamed with the Enterprise transporter the science officer? Shouldn't we have had a line with the assistant chiefs saying "But we round tripped those testing targets for five minutes straight! What changed?" or something to give the sense that it was human rated and they don't know why it's suddenly failed again.
B) If only one side has to handle the transport, as it's implied by almost every other transport shown in Star Trek, why did HQ beam Kirk to the station (when they could have landed him on the pad one-sided to the Enterprise), and why did Enterprise handle the beam-up of the science officer?
HQ and the Space Dock should have been handling all transports... Kirk should have been able to beam to the pad, and the Dock should have been able to land the new science officer the same way. If it was safe to beam from the other end, why would they decide to start using the Enterprise end for control?
Basically, I feel like I must be missing something big. Either I misread the Technical Manual about pad to pad transports, or I'm overlooking some episodes making it more nebulous, or that they DO explain the issue in the movie, but I was so hypnotized by the previous 6 hours of special effects and can't remember it...