Tub punctured after crash. When pumped up next day tyre doesn't lose any pressure, Help?

So last week I was in a crash. The result of this along with road rash and a lot bruises (lucky) was a pretty buckled front wheel and what appeared to be a punctured tubular. I got a wheel from neutral service and finished the race (Only around 3km to go).

I put my whole bike in the shop for a full look over anyway and lucky there was no other damage other than the wheels. The shop ended up truing both wheels and in the process obviously had to take the tubs off. It meant that when I collected my wheels the tubs we're off. However, neither me or the guys at the shop remembered which was the front tub. So when home, I pumped both tubs up to find out which one leaked air and result in finding the punctured tub. 2 days later neither lost any pressure. I put both tubs back on the wheel (without tape) and carefully rolled up and down my road for 10 minutes thinking maybe some pressure on them would cause the punctured one to deflate. This was to no avail.

So my question is, is this normal and one of the tubs is definitely still punctured? Which i assume is the case as it was completely deflated just after the crash and at the end of the race. Or is the tub some how OK and something possibly happened in the crash where it lost all pressure without puncturing?

Sounds ridiculous and this maybe a stupid question, but I can't think of anything else. Cheers.