What did Q's hint that a watch tells time tell James but not me?

Question

In Spectre, Q hands James a watch. Asking what it can do, he responds "It tells the time." A nice pun in what's also an ad for the Omega Seamaster 300.

In cinema, before the movie started, they actually showed that ad, which was somewhat disturbing, like seeing the trailer of a movie right before the movie. Maybe this biased my attention when the scene showed up in the actual movie.

in a car chase, James finds out that some of Q's accessories aren't that useful. Possibly Q did a half-hearted job on it because of what was supposed to happen to MI5 and the 00 agent program.

that means James knows that before the scene of interest to my question occurs:

being strapped to a chair James is tortured by Oberhauser Blofeld and after some time activates his watch which happens to be an explosive to escape.

I couldn't really tell if James is doing that intentionally, doing it intentionally but slowly to avoid attention or if he's merely finding the additional meaning of "it tells the time" by accident/luck.

The whole scene wasn't very convincing to me. In retrospect, maybe that's because the line "it tells the time", is some in-universe reference? There are a lot of references to other James Bond movies in this one. Did I miss anything? Did James know all the time that he could do what he did the way he did it?

I understand that part of the plot of a spy movie is to pull out surprise solutions to problems, but this one appeared to be surprising even for the spy.

Answer 1

First of all you seem to have gotten the line wrong. He tells him it tells the time and then later tells him that the alarm is quite loud.

I took it as simply as an ironic joke; a reference to the fact that all of Q's gadgets always seem to have some secret trick or tool but that in this case he's simply giving him a watch. The whole scene is filled with banter between Bond and Q in regards to how Bond treats the toys that Q gives him...

I thought I told you to bring [the car] back in one piece, not to bring back just one piece

The clue that he gives him that the watch is more than a just a watch comes when he warns him about setting the alarm.

Oh, one word of warning: The alarm is rather loud... if you know what I mean.

They then share a knowing look to understand that it does in fact do more than tell time and has a built in explosive device. While they may banter, and Q is limited in what he can provide to Bond while he is grounded, he still ultimately has Bond's back and provides him with an explosive watch.

EDIT:

In regards to the gadgets in the car not being useful, the car had been prepared for a different agent and obviously one with different tastes than Bond. I don't remember the exact details but there are three switches and as he flips them they each have an alternate meaning, adding to the humor of the movie. For example the "atmosphere" switch turns on "New York New York" adding to the "musical atmosphere" rather than serving as a possibly useful gadget such as nitrous boosters.

Answer 2

Perhaps Q, under the "new management" is not supposed to be arming Bond to the teeth with MI5's latest 00-ready weaponry, and makes this "tells the time" comment as cover/deniability, while still clearly letting Bond know that the watch "is loud"…