In that situation then ideally you would leave them in the ground until the leaves start to die back if you can. If you dig them up to heel them in there will be some root damage and in theory that may precipitate the foliage dying back and therefore less food made for the future. I'd be surprised if being dug up prematurely would actually kill the bulb though, but it may reduce flowering next year. But since you've already dug up half of them and have half still planted, you have a nice experiment set up there if you can keep the two groups separate when you replant, then you'll be able to tell if there was any negative effect on them when you compare them. Depending on the type of tulip they may not flower again for a few years anyway.
